3.8L Running Rich?
 

My 3.8L seems to be running rich -- the exhaust is extra stinky and rich smelling, the idle is slightly off/rough, but no codes or SES light -- any suggestions on what I should be checking first? I haven't started any research on this yet.

When was the last time the car was out and ran on the freeway for a good length of time? If it has been a while give it a go and drive it kinda hard to help break up any deposits in the cylinders. Make sure the MAF is not blocked and the air cleaner is good too. Next I would be looking at some o2 sensors and a good 'ol tune up.

Massey

LOL, it has new plugs & wires, new O2 sensors, but could use some fuel treatment and some highway driving...

Check the MAF, I was having problems with my wife's car shortly after we first brought it home and I found that the rubber tube that connects the air silencer to the MAF was only 1/2 on and a leaf got stuck in there. Not enough air, engine ran too rich.

Massey

Wow, how ironic -- I just got the O2 PO153 code for Bank 2, Sensor 1! I am having a recurring failure issue with O2 sensors, and I am unsure why -- any ideas? Current O2's are NAPA...

Nobody has any ideas related to the sensor failure? Just assume a bad batch of O2 Sensors? Replacement of the sensor was the fix for this code.

I had a similar problem I replaced one of the o2 sensors on my car. Not the other one. Well my car was running rich I looked and looked and couldn't find anything. I went to a junkyard and got almost all of the engine sensors and replaced them. I still had the problem. Turned out my other o2 sensor was loose. I hadn't touched it. It was loose enough that I belive it was sucking in air and making it run rich I pulled it out cleaned it put some anti seize and presto... it wasnt running rich any more. Also I've had bad experiences with advance auto parts with there electronics. I just bought and ignition module that didn't work at all. Just a thought for ya

Joe, The ignition module you had a problem with is the reason why there is a warranty, BWD is the top brand going right now and while the failure rate is low it does sometimes happen, and it happens to ALL manufacturers.

Liberty. Is the O2 sensor a NAPA brand or was it Bosch? I dont like using anything other than the Bosch brand O2 sensors. They just seem to work better than the rest and GM must think so too since Bosch is GM's supplier.

BTW do you all know that NAPA is an Acronym?

No Auto Parts Available, but when they do have a part they are Nasty A$$ Parts Anyway.

Massey

Lol. I don't really go to napa usually there parts are way over priced. And half the time they never have what I need. Bosch is okay. I mostly like the ac delco parts. But yea I belive I hard recently that Bosch is making all the gm electronics now. The Oriely parts I get are master pro. I've had good luck with there parts. The o2 sensors I replaced in my car are Bosch. I just don't like there plugs. I would rather have ngk iradium plugs.

I work at O'reilly and I would not buy the Master Pro stuff for my own car. They are not as good as the BWD parts. I used to like the Niehoff stuff but I dont know who sells that any more. Neihoff is a BWD brand and most of the time it was the same part as the BWD stuff just in a different box. The Master Pro is more like Standard (same as the NAPA brand) stuff and while Standard used to be the best stuff they have fallen pretty far off the lead after they moved all their production to China.

Massey