Well i fixed one problem ( tps) but my Ram with the 5.2 still is running lean. What i am wondering though is my IAC was whistling back when the TPS went out on it, so i cleaned it with sensor safe cleaner, dried it out, then put it back in. Now it doesn't whistle anymore but my truck is still running lean. Exact error is P0171 too lean, bank 1. This is a 1997 dodge ram 2 wheel drive, automatic. Now the truck does have straight pipes on it, with the o2 sensor behind the cat unpluged. It was like that when i bought it 3 yrs ago and just recently started to have problems so i am assuming that isn't the problem. Any one here got any ideas on what could be the problem or maybe point me in the right direction?

 

The o2 sensor behind the cat is unplugged from the ehaust pie or unplugged from the electrical connector?

 

How many miles on that pre-cat oxygen sensor? As they near end of life, a lean running condition is normal -- normal as in "expected to happen", not normal as in good.

 

The o2 sensor behind the cat is unplugged from the harness. The pre-cat sensor, and this is a quess, has never been changed. The truck has 137,000 miles on it.

 

Replace front O2 sensor, and report back. Another reputable poster I know on another forum informed me that Bosch O2 sensor tend to run a bit richer than others.

 

^++. It's time for a new pre-cat oxygen sensor.

 

OK, i'll pick up a new pre cat 02 sensor friday and give er a try. None of you guys think the iac is involved in this??? This is my first dodge so i'm kind of reaching on this.

 

The IAC only comes into play when the throttle is fully closed, so if you're lean under any other condition the IAC cannot be implicated.

 

ok, thank you for the explanation. I will post the results this weekend, allthough i might try cleaning it tomorow after work to see if it atleast helps. I've got nothing to loose using sensor safe cleaner.

 

wow, took the pre cat sensor out today to clean it up and the end looks like it has been smashed. I have never seen one look like that. The guy who used to own my truck really did a number with his home made custom exhaust job. I even had to cut the welds off the tail pipe when i first bought it because he didn't want it to rattle. I guess he didn't think a bit of flex in an exhaust system was a good idea. Anyways i bet he smashed the 02 sensor while hallowing out the cat and it has just now totally stopped working. Well thats it for todays update, i'll post more when i pick up the sensor friday afternoon.[ATTACH][/ATTACH]