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06 BAJA EJ251
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Discussion Starter #1 (Edited)
I have been battling an 06 baja for a month or so. Even though its an 06 it has an ej251 na 5spd. Car runs great in OL but once it get get warmed up it has major power issues. The only code i can get it to throw is rear o2.(waiting on a new one to arrive) I have very limited live data due to a sloppy obd2 connector. Here is what i have done so far, New plugs, coil, map, checked vac,fuel pressure,new knock sensor, adjusted tps, I bought a temp sensor and instead of screwing it into the block i just zip tied it on the intake making the vehicle stay in OL. My question is what sensors come into play with the CL. Below is a link the a live data log. I am trying to get the obd2 connector issue fixed so i can run more data.
 

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2001 VDC/SC One of a Kind
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OL is a cold start and anytime you accelerate beyond a set point in the ROM. Generally this is anywhere from 50-80% accelerator position. The computer runs a totally different fuel map in OL. The transition from OL to CL occurs when the front AF sensor heater circuit resistance drops to around .3. The ECM will continue to fuel the car based on other factors like ECT, TPS, RPM, MAP and speed until it reaches operating temperature, above 158°F. It then manages fuel based on feedback from the AF sensor, continuing in CL until the accelerator is pushed passed the threshold and other factors like ECT, TPS , RPM, Load, and MAP are factored in.

I don't know if you are getting your fuel maps confused or not. The car runs in CL from about 30 seconds after a start up until it needs to go to the OL fuel map for whatever you are asking the car to do. In OL fueling, the emission efficiency is ignored; the rear O2 data is not used as an efficiency monitor, but rather a fueling monitor. You'll notice if you floor the accelerator, the EM goes OL, the fueling is heavy, the STFT goes to zero and the rear O2 should go up above .9V. and stay there until you let off the throttle and the ECM changes fueling and the cat starts operating again.
 

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2012 OB , 2017 Impreza
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I agree with CarDoc analysys on this one. It sure sounds as if CL is the issue.

Instead of throwing parts at it, consider MONITORING some of the key sensors whilst driving to determine what is going on. Be aware that just because a sensor is showing unexpected readings, its DOES NOT mean that sensor is faulty. Instead, it is more often telling you the TRUTH and you need to troubleshoot to isolate the REAL problem.

I tried clicking on your link and it only shows me a blank page asking me to make a new post.
 

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06 BAJA EJ251
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Discussion Starter #4
I agree with CarDoc analysys on this one. It sure sounds as if CL is the issue.

Instead of throwing parts at it, consider MONITORING some of the key sensors whilst driving to determine what is going on. Be aware that just because a sensor is showing unexpected readings, its DOES NOT mean that sensor is faulty. Instead, it is more often telling you the TRUTH and you need to troubleshoot to isolate the REAL problem.

I tried clicking on your link and it only shows me a blank page asking me to make a new post.
Yeah i got the CL OL backwards, and i fixed the link, thanks for pointing that out. As of right now i have a second temps sensor that is plugged in and not screwed into the block this keeps the temp around 135 when warmed up and the car runs great, as soon as i plug the temp sensor in that is in the block the car lacks most of its power, feels like the intake is restricted.
 

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06 BAJA EJ251
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Discussion Starter #5
OL is a cold start and anytime you accelerate beyond a set point in the ROM. Generally this is anywhere from 50-80% accelerator position. The computer runs a totally different fuel map in OL. The transition from OL to CL occurs when the front AF sensor heater circuit resistance drops to around .3. The ECM will continue to fuel the car based on other factors like ECT, TPS, RPM, MAP and speed until it reaches operating temperature, above 158°F. It then manages fuel based on feedback from the AF sensor, continuing in CL until the accelerator is pushed passed the threshold and other factors like ECT, TPS , RPM, Load, and MAP are factored in.

I don't know if you are getting your fuel maps confused or not. The car runs in CL from about 30 seconds after a start up until it needs to go to the OL fuel map for whatever you are asking the car to do. In OL fueling, the emission efficiency is ignored; the rear O2 data is not used as an efficiency monitor, but rather a fueling monitor. You'll notice if you floor the accelerator, the EM goes OL, the fueling is heavy, the STFT goes to zero and the rear O2 should go up above .9V. and stay there until you let off the throttle and the ECM changes fueling and the cat starts operating again.
Yeah i got OL and CL confused then writing. Would you think this issue is due to issues with the AF since the problem is not there when i run the car with the temp sensor plugged into a second sensor that isn't installed keeping the temp under 158deg?
 

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2001 VDC/SC One of a Kind
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Could be. Could also be in the ECM. I've not seen it in an ECM as if yet.

Battery
Grounds
Sensor feedback
Manipulation

It appears CL temp is related to the issue based on your posts.
 

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06 BAJA EJ251
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Discussion Starter #7
Could be. Could also be in the ECM. I've not seen it in an ECM as if yet.

Battery
Grounds
Sensor feedback
Manipulation

It appears CL temp is related to the issue based on your posts.
Ground and battery are good, added extra grounds. Which sensors should I start looking at, and what do you mean by manipulation? The ECM has been in the back of my mind, I have been sourcing some used ones.
 

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2008 Outback 2.5
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I have very limited live data due to a sloppy obd2 connector. I am trying to get the obd2 connector issue fixed so i can run more data.
My 08 OBW also has a sloppy OBD2 receptacle and it was causing false codes to be thrown and putting the car into limp mode until I reset it with the OBD2 scanner. I bought one of these splitters for $8:


to use as a "connector saver" so that it stayed on the car permanently while I plugged the OBD2 dongle into one of the Y-cable receptacles. I do remove it when going into a smog station for the bi-annual smog inspection.
 

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2001 VDC/SC One of a Kind
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Sensor feedback from the engine management sensors. Manipulation is the ECM's job.

The main signals are the AF, O2, MAF, TPS, ECT and RPM. Cam sensors determine fuel timing. Crank determines ignition timing. The others play a role in performance and efficiency while protecting the catalytic converter. The ECM reaction is based on mathematical equations written in the ROM. It also learns based on feedback from the sensors and judges performance output and changes it's perameters to make improvement.

This is seen in the way the data feedback changes with input from the driver. High load with detonation, the ECM adjust fuel and timing to make it stop. High voltage feedback from the AF sensor(s), it adds fuel to prevent detonation and misfires along with preventing high exhaust temperatures, which burns up substrate. Low voltage results in reducing fuel to insure the cylinder isn't running too rich which can cause a misfire and overloaded exhaust and catalytic converter.

A lot of factors are involved in maintaining engine operation in such a way that the engine will output the torque and HP required of it while also keeping emissions low, whether highway cruising or accelerating on a hill while pulling a trailer. It always comes down to power management and proper feedback in conjunction with a properly maintained engine and transmission. If there's a problem with the mechanical, the sensors will see it and the ECM will manipulate the engine parameters to try to fix it. There could be zero mechanical issue and a sensor is throwing the balance off and the corrections made in one area will affect others and then those sensors act wonky. All bringing the performance down.

Data from the car in segments of time can tell a lot. Freeze frame is only good when a code sets at start up, like crank or cam codes, air pump on CARB cars, some emission codes and the like. But with majority of engine performance and trans codes you have to look at data and know what you are looking at and how one sensor's feedback should correspond with another's. And when I manipulate a segment of air, fuel or fire I want to see the reaction from the sensors to correspond with what I'm doing. The same way the ECM does it in testing the performance or system components.

I have a lot of data logging information in the P0420 Diagnosis thread. Much of the time the catalytic converter has not been the issue and the problem was found in the engine's performance through looking at data. Things like OCV, timing, battery, cabling, sensor errors, alternator, TCC slip, brakes, bad AF sensor, knock sensor, dirty throttle, clogged PCV or cracked vacuum hose. Any one thing or a few can cause any number of issues. And the data can narrow down where to look.
 

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06 BAJA EJ251
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Discussion Starter #10
Sensor feedback from the engine management sensors. Manipulation is the ECM's job.

The main signals are the AF, O2, MAF, TPS, ECT and RPM. Cam sensors determine fuel timing. Crank determines ignition timing. The others play a role in performance and efficiency while protecting the catalytic converter. The ECM reaction is based on mathematical equations written in the ROM. It also learns based on feedback from the sensors and judges performance output and changes it's perameters to make improvement.

This is seen in the way the data feedback changes with input from the driver. High load with detonation, the ECM adjust fuel and timing to make it stop. High voltage feedback from the AF sensor(s), it adds fuel to prevent detonation and misfires along with preventing high exhaust temperatures, which burns up substrate. Low voltage results in reducing fuel to insure the cylinder isn't running too rich which can cause a misfire and overloaded exhaust and catalytic converter.

A lot of factors are involved in maintaining engine operation in such a way that the engine will output the torque and HP required of it while also keeping emissions low, whether highway cruising or accelerating on a hill while.pulling a trailer. It always comes down to power management and proper feedback in conjunction with a properly maintained engine and transmission. If there's a problem with the mechanical, the sensors will see it and the ECM will manipulate the engine perqmeters to try to fix it. There could be zero mechanical issue and a sensor is throwing the balance off and the corrections made in one area will affect others and then those sensors act wonky. All bringing the performance down.

Data from the car in segments of time can tell a lot. Freeze frame is only good when a code sets at start up, like crank or cam codes, air pump on CARB cars, some emission codes and the like. But with majority of engine performance and trans codes you have to look at data and know what you are looking at and how one sensor's feedback should correspond with another's. And when I manipulate a segment of air, fuel or fire I want to see the reaction from the sensors to correspond with what I'm doing. The same way the ECM does it in testing the performance or system components.

I have a lot of data logging information in the P0420 Diagnosis thread. Much of the time the catalytic converter has not been the issue and the problem was found in the engine's performance through looking at data. Things like OCV, timing, battery, cabling, sensor errors, alternator, TCC slip, brakes, bad AF sensor, knock sensor, dirty throttle, clogged PCV or cracked vacuum hose. Any one thing or a few can cause any number of issues. And the data can narrow down where to look.
awesome response... I will check out and study your link. I was watching some live data from my handheld scanner tonight and watching the ignition timing. With the dummy temp sensor plugged up (keeping the car in CL) my ign timing advanced never went below 10deg. and the car ran good. As soon as i plug my installed temp sensor (putting the car in OL) when i was pulling out on hills the ign timing advanced would drop into the negatives from -1 to -10 deg. this would explain the lack of power for sure. I am guessing this could be from a bad crank or cam sensor? I have installed a new knock sensor. My timing belt kit is in so I am going to change it out within the next couple of days. I will check the cam and crank sensors as well...
 

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The negative numbers would be due to knock, or detonation, in one or more cylinders. If it's not doing it with the sensor laying out while driving, but doing it with the installed sensor then it wouldn't be a crank or cam sensor as much as it is something related to the fuel map. Timing, fueling and air metering.

Do you have the knock sensor turned at 45° to the crank line and the connector pointing rearward?
 

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06 BAJA EJ251
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Discussion Starter #12
The negative numbers would be due to knock, or detonation, in one or more cylinders. If it's not doing it with the sensor laying out while driving, but doing it with the installed sensor then it wouldn't be a crank or cam sensor as much as it is something related to the fuel map. Timing, fueling and air metering.

Do you have the knock sensor turned at 45° to the crank line and the connector pointing rearward?
Yup, installed a new knock sensor 45 deg connector facing to the rear. I am totally lost. I have had several people say its a bad ecu. I am really not sure what else it could be. It retards the timing when under heavy load.
 

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I bought a temp sensor and instead of screwing it into the block i just zip tied it on the intake
That difference in the way the engine runs between the ECT sensor in the coolant, and the one zipped tied on the intake, is puzzling.

Does the sensor used on that Baja 2.5 have three terminals in the connector? If so, when the new one was zipped tied, was the metal housing of the sensor making a good grounding connection to the intake (presuming the intake is metal, not plastic)?

When the log from July 16 was made with the zipped tied sensor, did the temperature gauge in the instrument cluster work, i.e., in the latter half of the logging period, was the pointer at the "normal" position?

In the July 16 log, the ECT goes from 149-187 F. It's at 187 F for the latter half of the log. 187 F is close to normal. And the car seems to have been performing well.

In the more recent log, the ECT goes from 190 F to 198 F. This is higher, but still in the "normal" range. Yet, this log shows the engine unable to accelerate at what appears to be wide-open-throttle. Was this with the zip-tied sensor, or the one in the engine?

@cardoc In the last log there's a 12-second period (between approx 11 seconds and 23 seconds) where the throttle is high, MAP is high, yet the car is slowing. I'm puzzled about other parameters such as Injector duty cycle which, during this same period, is dropping.
 

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Discussion Starter #15
That difference in the way the engine runs between the ECT sensor in the coolant, and the one zipped tied on the intake, is puzzling.

Does the sensor used on that Baja 2.5 have three terminals in the connector? If so, when the new one was zipped tied, was the metal housing of the sensor making a good grounding connection to the intake (presuming the intake is metal, not plastic)?

When the log from July 16 was made with the zipped tied sensor, did the temperature gauge in the instrument cluster work, i.e., in the latter half of the logging period, was the pointer at the "normal" position?

In the July 16 log, the ECT goes from 149-187 F. It's at 187 F for the latter half of the log. 187 F is close to normal. And the car seems to have been performing well.

In the more recent log, the ECT goes from 190 F to 198 F. This is higher, but still in the "normal" range. Yet, this log shows the engine unable to accelerate at what appears to be wide-open-throttle. Was this with the zip-tied sensor, or the one in the engine?

@cardoc In the last log there's a 12-second period (between approx 11 seconds and 23 seconds) where the throttle is high, MAP is high, yet the car is slowing. I'm puzzled about other parameters such as Injector duty cycle which, during this same period, is dropping.
Yeah i am totally confused. Both logs are with the temp sensor installed. Its the 3 wire one. When i use the dummy sensor its not grounded, just zip tied to a wire. The car good with the dummy sensor with just a little hesitation. That last 12 seconds I was pulling a steep hill in second gear and it was just falling on its face. I am going to try the same dummy sensor idea with the knock sensor, to see if maybe the signal coming from the knock sensor is what is making this happen. I have had knock sensors do weird stuff in the past.
 

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Both logs are with the temp sensor installed.
I presume you mean the one installed in the engine -- not the zip-tied one.

The only difference in this regard between the July 16 log (post #1) and the July 27 log (post #13) is that the ECT is somewhat lower in the earlier one, i.e., it goes up from 149 to 187 F, whereas in the latter log its 190 to 199 F. Yet the first log appears to show the engine pulling well, whereas in the second, between 11 and 23 seconds, it can't accelerate, indeed loses rpm and speed, despite appearing to be at WOT.

I had though the difference was because in the first log it was the zip-tied sensor, and in the second, the installed sensor. So, now, two logs, not all that different ECTs, at least during the latter part of the second log, yet very different symptoms (if I'm interpreting the logs correctly).

@cardoc ?
 

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2010 Outback 3.6R 2014 Legacy 2.5i 2003 Legacy L special edition (retired to backup)
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what does the exhaust smell like when it is running poorly?
 

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06 BAJA EJ251
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Discussion Starter #19
I presume you mean the one installed in the engine -- not the zip-tied one.

The only difference in this regard between the July 16 log (post #1) and the July 27 log (post #13) is that the ECT is somewhat lower in the earlier one, i.e., it goes up from 149 to 187 F, whereas in the latter log its 190 to 199 F. Yet the first log appears to show the engine pulling well, whereas in the second, between 11 and 23 seconds, it can't accelerate, indeed loses rpm and speed, despite appearing to be at WOT.

I had though the difference was because in the first log it was the zip-tied sensor, and in the second, the installed sensor. So, now, two logs, not all that different ECTs, at least during the latter part of the second log, yet very different symptoms (if I'm interpreting the logs correctly).

@cardoc ?
The first log is different because i was not putting the car under so much of a load. The second log i was pulling out from the bottom of a steep hill and going up the hill. it seems the more load the more my timing is pulled.
 

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Discussion Starter #20
Quick update, So i installed a dummy knock sensor about the same way i did the temp sensor but I used a wire to ground the sensor so it does't throw a code, and i plugged in the installed temp sensor so the car would go into CL. I didn't get to drive it as much as i would have liked to but from what i can tell with the dummy knock sensor installed it ran good. I have heard of overactive knock sensors making cars run bad, the car doesn't have any bad knocks to the engine, it runs about like any other subaru i have had in the past (like a sewing machine). I am thinking the knock sensor is sending bad readings to the ecu and its pulling timing. i would think it should be advancing the timing though. I thought about putting a damper (rubber washer) under the knock sensor to see if that will help, it should in theory still pick up knocks thought the mounting bolt, but be less sensitive
.
 
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