[only126db]

What is the EGR code?

I believe it was the po400, but after tightening up the knock sensor which was literaly a couple bolt threads from being free hanging, my check engine light has stayed off and it is running good again. My exhaust leak is just past the downstream cat so besides a little noise I dont believe it effects performance, its just a pin hole in a weld.

I am thinking that loose knock sensor was making the computer try to figure out what the heck it was supposed to do but it wasnt a failed part so it was thinking "it works nope not working, yup, nope ,yup, nope ,yup wtf????" And all it could do was toss out codes to say "hey stupid in the drivers seat, we got a problem"

I will do some more driving in the next couple days to make sure, but so far seems ok.

 

[only126db]

Went for a drive, got 31mpg but also got these codes.

P0400: Exhaust Gas Recirculation Flow
P0420: Catalyst System Efficiency Below Threshold (Bank 1)
P0404: Exhaust Gas Recirculation Control Circuit Range/Performance
D00: Unknown code - More information may be available on the web

on the way home got 29.6mpg but no codes


p.s. forgot to mention they were pending codes no CEL

 

[cardoc]

There is a relationship between the EGR and P0420. And if the MAP is still showing odd data, it needs to be looked in to.

The ECM uses MAP data to check EGR function. When the EGR is open it essentially creates a vacuum leak which alters pressure in the intake which would change the MAP value. If the ECM doesn't see a change in MAP, it assumes EGR flow is inefficient or there is a control problem. And as before, the MAP pressure also determines fuel trim and if its running to rich or lean will cause an efficiency drain on the CAT. But we already know your CAT is bad. We just don't have certainty where the malfunction in trims started.

It's good that it is running better, but you still need to find all the faults.

 

[only126db]

There is a relationship between the EGR and P0420. And if the MAP is still showing odd data, it needs to be looked in to.

The ECM uses MAP data to check EGR function. When the EGR is open it essentially creates a vacuum leak which alters pressure in the intake which would change the MAP value. If the ECM doesn't see a change in MAP, it assumes EGR flow is inefficient or there is a control problem. And as before, the MAP pressure also determines fuel trim and if its running to rich or lean will cause an efficiency drain on the CAT. But we already know your CAT is bad. We just don't have certainty where the malfunction in trims started.

It's good that it is running better, but you still need to find all the faults.

If i remember correctly my MAP was from 2.5-3psi at idle right before my trip which converts to 5-6 inhg roughly.

fuel trim was .8

and the rest i cannot remember, i did take a snap shot of my cruising numbers but i think i accidently deleted it, phones been acting crazy.

found it...

cruising @ 55mph with cruise control on

 

[only126db]

will the bad cat possibly throw a p0400?

cel came on, got the p0400 and catalyst insufficiency one.

cat is on order....

p.s. new tps made no difference, kept the old one on and put the new one in a box i am collecting parts and pieces in.

 

[rasterman]

I recall that the 400 is the EGR valve. My old '98 would toss this one occasionally. I tried a few fixes but couldn't permanently clear it until I replaced the EGR valve.

 

[only126db]

I recall that the 400 is the EGR valve. My old '98 would toss this one occasionally. I tried a few fixes but couldn't permanently clear it until I replaced the EGR valve.

my egr itself wasnt really too dirty, moves smooth, seals well and holds vacuum so its not the egr itself, i tried my best to clean the intake port, checked the hoses, all seems good, didnt test the bpv or solenoid or whatever you call it.

 

[only126db]

cardoc

i was just thinking....i have two cats...i only ordered the front....i will probably need both wont i?

 

[subiesailor]

cardoc

i was just thinking....i have two cats...i only ordered the front....i will probably need both wont i?

Doubt it. I damaged my front cat drove on it for 5yrs with a crack right at the Y just infront of the first cat. 5yrs of road grime sucked into the front cat eventually killed it. New Ypipe cost me like $290 online subaru parts store - took me 40 minutes to replace the ypipe. Then had the local ma and pa muffler shop cut out the old front cat and drop in a new one $150 while I ate lunch across the street. New OEM front O2 sensor and a after market O2 on the back end and all was fine for another 45K at which point the car was sold with zero issues.

Dealer would have charged me not kidding $2900 for the same job.

 

[only126db]

Doubt it. I damaged my front cat drove on it for 5yrs with a crack right at the Y just infront of the first cat. 5yrs of road grime sucked into the front cat eventually killed it. New Ypipe cost me like $290 online subaru parts store - took me 40 minutes to replace the ypipe. Then had the local ma and pa muffler shop cut out the old front cat and drop in a new one $150 while I ate lunch across the street. New OEM front O2 sensor and a after market O2 on the back end and all was fine for another 45K at which point the car was sold with zero issues.

Dealer would have charged me not kidding $2900 for the same job.

i ordered a rear just for the heck of it. Cheapest i could find was almost $400 for both cats, nobody local has them. I also read that a messed up cat can possibly mess with the map, which cardoc said was reading incorrectly. I am thinking the front cat is just totally toast and may be messing stuff up. It wont hurt to have fresh cats all the way around. I have avraged 28-31mpg and thats with my car running rich (per cardoc) so if i get it going better, i see 30-35mpg in my future. Much better than the 12-16mpg i was getting with my durango.

 

[only126db]

Finally got around to checking out the map sensor, I think I did it wrong...

key on engine off i got a static reading of 3.5v before applying vacuum.

anyone know if thats what I should have?

 

[only126db]

no help???