LT'S and ORY + new wires, AC DELCO IRIDIUM plugs, 13111 bosch 02 sensors, have air and egr hooked up...02 sims for rear...got scanned..both banks running a little LEAN...thought I should be running RICH...it even smells like I am rich.?? WHAT GIVES ??? ..........

 

What parameter did you scan to determine you are running rich?

 

I am running LEAN apparently..I do not know which parameters or what---I had this done..I didn't do it myself..I have always used injector cleaner also [someone else inquired about my injectors??] car is running almost as well as before headers now...like I said, I thought it should be rich..not lean..

 

I ask because many times people say the car is running lean when it really isnt. That is because that is what fuel trimming in the PCM is for and they are based on oxygen sensor activity. When you add the headers, initially you may run a bit rich, but the PCM will learn it quickly and adjust the fuel trimming to maintain 14.7 AFR. The car will not run lean or rich, the PCM will adjust to keep it at 14.7.

If you are really running rich then there is a problem such as an intake vacuum leak, fueling problem, or sensor problem.

 

OK...will check these...will getting my injectors/fuel system cleaned help..I would hear an intake leak wouldn't I ?? have not touched intake. ..sensor problem?? I just installed new 13111 02 sensors...any advice is welcome..

 

Autozone and Advance Auto show 13444 to be the right oxygen sensor for your car, not 13111. Maybe thats a problem, although I know others use 13111 also.

Getting the fuel system cleaned will help if it is clogged up, which can happen to our rails since they dont have a return back to the tank. I would run some seafoam through the gas tank and replace the fuel filter first. An intake leak you can usually hear and usually the idle RPM will go up a bit with a decent leak.

Get that oxygen sensor issue checked first.

 

I cannot hear any leaks, fuel filter was changed awhile back, but obviously wouldn't hurt to do that again....install was thursday night...about 250 miles put on it and it is running better than it was yesterday..yesterday better than the day before...maybe the pcm is still learning..another member I pm'd said it took his over 500 miles until it stopped running crazy...after the install it was running rich--I could smell it fairly strongly...

 

13444 ???? I have the wrong sensor ??? ..everyone told me 13111.

 

I notice many people use 13111 and it may be OK but autozone and advance call for 13444. Im not sure if they are interchangable.

 

Very common after installing LT's. Airflow characteristics are much different and the O2 sensors are now farther from the heat. The PCM will trim, but not truly learn how to make up the difference. A tune sometimes is your best bet.

 

THANKS both of you...BTW...Anybody having trouble when they click 'New Posts' ???? I just get yesterday and before ??

 

Good point! They sensors will be a little scewed still since they arent as hot as they should really be due to them being down the exhaust stream so much. Yeah tuning is always the best way to go.

 

Which is why people told him to get the Bosch 13111 02 sensors (vette rears), they have a hotter sensor element.

 

I knew there was a reason that I noticed others are using those sensors too. I didnt know they ran hotter. Thanks.

 

No prob, I got them also once my stock 02s couldn't get hot enough because of the longtubes.

 

Check that you still have the EGR seal on the intake manifold pipe.

When I had my LTs installed the seal fell off the pipe and wasn't noticed. The care idled like crap and when I scanned it my STFT would go to + 15 - +20 at idle and the LTFT would then max at +25.

Without the seal on the EGR pipe you are introducing unmetered air into the fuel delivery system (after the MAF). I scanned it for DTCs as well and both banks had trouble codes for running lean.

I listened around and could hear a faint hissing around the EGR pipe. I threw a rag over it and the hissing noise reduced. After replacing the EGR seal and resetting the PCM it idles perfect and the STFT and LTFT are right back to normal.

 

THANKS...sent you a PM.