plug issues. resolved but why?

[bobrunner6689]

My 2000 subaru outback had a misfire so the dealer replaced plugs and wires. they said that the plugs that i had used didnt work well. Normally i wouldnt have a problem with a mechanic telling me that but before i bought it my uncle had the plugs replaced with bosch platinum plugs. is there a reason why they dont work well with my engine?

[nipper]

Yes. Subaru uses a waste spark ignition, that means two plugs fire at the same time 1-2 and 3-4. They are sensative to what plugs you use, as you really need to use OE recomnded sparkplugs. There are other cars that are sensative to this too.

Same goes for the wires, as they should be OE at the very least.

nipper

[gryffinwings]

I'll contest that the Bosch plugs suck for our cars, I used the Bosch Plat/IR Fusion and they didn't last long before I was getting misfire codes. You have to use OE or similar, NGK Iridiums are good, Denso Nippon plugs should work too since they are practically the same.

[deadlydave]

Originally posted by gryffinwings
I'll contest that the Bosch plugs suck for our cars, I used the Bosch Plat/IR Fusion and they didn't last long before I was getting misfire codes. You have to use OE or similar, NGK Iridiums are good, Denso Nippon plugs should work too since they are practically the same.

I agree. Bosh makes plugs for a broad range of vehicles--they make a ton of 'em, but the quality is Meh. Companies like NGK and Denso make less of a variety, and more application-specific pieces, so better quality.