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Mattyj724
05-01-2010, 12:52 PM
iv searched a little and i can never get a good answer. iv put a CAI and a pacesetter exhaust on with a tuned PCM from mark and the high grade fuel. now i throw a code like 2 time a month for running lean. What parts should i check and replace? it has 97K on it!!! any advice?

AaronGTR
05-01-2010, 02:56 PM
Ever replaced the O2 sensor? Those do wear out after a while. They are recommended to replace at least every 100k miles... I've found they often need changing sooner. If it's never been changed, you are definitely at the mileage to change it, regardless if it's causing the lean code or not. Your fuel trims should get more accurate and gas mileage should increase. Also when was the last time your fuel filter was changed?

stillriza
05-01-2010, 06:56 PM
Aaron, how hard is it for someone to replace the O2 sensor themself on our cars? I've been getting pretty crappy mileage but I know its becuase i am way over due for a tuneup (plugs/wires/filters). I figure I should prob change the O2 sensor as well since I have roughly 170k on the car without it being changed previously.

Grandamgtblk99
05-01-2010, 08:53 PM
Aaron, how hard is it for someone to replace the O2 sensor themself on our cars? I've been getting pretty crappy mileage but I know its becuase i am way over due for a tuneup (plugs/wires/filters). I figure I should prob change the O2 sensor as well since I have roughly 170k on the car without it being changed previously.

It's pretty straight forward. You can usually rent the oxygen sensor tools from an auto part store to help you remove them. Best thing is to spray it down with some PB blaster the night before to help loosen up the rust. It pretty much just screws out and screws in.

AaronGTR
05-01-2010, 10:35 PM
Yep, they are usually rusted in pretty well on the stock manifolds, so use lots of penetrating oil and let it soak in. Shouldn't need any special tools to get it off though. Just a 7/8" open end wrench. I guess if that doesn't work you could use one of those O2 sensor sockets or whatever. Never needed one myself. Sometimes heating up the metal around it with a propane torch helps loosen up rusted stuff like that too.

Grandamgtblk99
05-02-2010, 04:52 PM
Or I supposed you could just let the car get to operating temp and try and do it. But it'd make getting your hands down in there a pain in the butt.

Mattyj724
05-03-2010, 12:47 AM
the fuel filter was changed around 60K so im assuming that its ok.. ill take a look at the o2 sensor.. there are 2 right?? one on the CAT and the other is before that but where?

AaronGTR
05-03-2010, 04:28 PM
One is behind that cat and that only checks to make sure the cat is working. Has nothing to do with fuel adjustment. The main O2 sensor is in the top of the rear exhaust manifold up by the engine. If you take out the ignition module with the coils on it you can see down in there and get to it with a wrench.

Mattyj724
05-06-2010, 11:49 PM
ok so....... replaced all 6 Spark plugs with ac delco platinum and the first O2 senors.... The car runs great and has restored power. we will see about the gas mileage...