The past couple months i've had some idle problems. Whenever i start the truck the idle fluctuates from about 500-1800. It dosen't ever stay in one spot. Then it got so bad that when i put in reverse or drive it would drop to around 0 rpm's and stall. I took it to the mechanic and told him what was goin on. They replaced the IAS motor i think? It was something like that. I got it back and it ran fine for about a week and a half. Then it started again.. Stalling and sporadic idiling. Same as before. Took it back and the vapor canister (an emmissions componet) was busted and there was charcoal in the vaccum lines. So they replaced that and cleaned the lines. Got it back ran fine for a week and then guess what? Started again! I think my catalytic converter is bad. At about 1800 to 2300 rpms it sounds like there are marbles in it bouncing around. The problem is starting to **** me off. Does anybody have any suggestions? Any help is appreciated. Btw my truck is a 1997 1500 with 5.2 in it. 180,000 miles.

Thanks

 

have you checked your TPS? you think they replaced the IAS (taking it you mean Intake Air Sensor) always heard it refered to as Idle control sensor or IAC you might wanna find out if that was changed sounds like it could be going bad. the cat does sound like its shot from what you say

 

I was reading about the TPS. I'm gonna tell them to check that out. Yea, im going to replace the cat

 

i had both my IAC and TPS go out at the same time and it sent my truck for a loop didnt know what was goin on with it

 

Did yours ever stall out?

 

it did once or twice so im guessing it was the TPS causing it. mostly it would act like it wanted to bog out when i backed out of my driveway which was uphill and stopped on the road

 

You can check your TPS your self with out taking it to a dealer, simply unplug it and turn the truck on, push the gas and then let off of it, if the RPM's stay high then it's not going to be a TPS issue.

Just dont forget to plug it back in after you're done.

 

just replace the TPS with one from autozone for $39.

i've replaced mine a couple of times for "surging idle" problems, including just tonight. sometimes it'll throw a P0121, 122, 123 code as proof, but sometimes it won't.

mine was reving up to 1500 at start, and then bouncing around 800-1000 and then when letting off the gas it would drop way down and kind of jerk the transmission around.

here's a tip - if you replace a sensor that doesn't solve your problem, then keep the old one and label it as good and keep it as a spare. then when you have a problem put that spare one on. the damn IAC and TPS tend to fail.

also - always reset the PCM after replacing these.