2004 Aveo, idling 1500-2K rpms. Runs fine all gears, manual trans. SOLVED: vac leak

[Radiance_Komer]

Ok, So tomorrow I will replace that and we can go from there. I can hear an air leak up around the TCS, it sounds like it is coming from down behind there. I felt around but couldn't find anything off hand. It was dark out by then. I'll try again with that tomorrow. I wiggled around on things and when started messing around with the whole throttle area the rpms went down then right back up then almost hit 3,000 then back down. I am guessing there is an issue in that area. I think I hear some kind of electrical feedback after the car is shut off from the plug there. Sorry, I am not good with names on parts. I am just like...that black plug that goes into the silver thing. lol.

The p0134 indicates NO response from the upstream O2. But if it's actually reading erratic (sometimes nothing, sometimes ok), then just about any engine weirdness is possible.

The usual suspects for high idle would normally be a bad IAC or vacuum leak. However, with a specific O2 code such as the P0134, you want to get that resolved first, and then see where things stand after that code has been eliminated.

[avguy]

Ok, So tomorrow I will replace that ...

As I wrote previously, you should check the wiring/connector before hanging on a new part. Not a difficult thing to do, with just a fairly inexpensive multi-meter needed to do the testing.

[Radiance_Komer]

Ok, so here is where we are at....

Replaced the o2 sensor...in that found out that there is no catyliyic converter on the car. Someone has replaced it with a strait pipe. I'll get that delt with later. After taking to muffler shop to make sure that something didn't get messed up when that was done the mechanic said after looking over the car that there is def a vac leak. So I started poking around and discovered that the air filter cover is all busted down the side. there is a chunk that would complete the seal around it. I have a new one ordered online. In the mean time, Autozone helped me put a seal around it temp. once it dries we will see if that helps with the RPMs. Here's to hoping it was that simple!

[Radiance_Komer]

Ok, so here is where we are at....

Replaced the o2 sensor...in that found out that there is no catyliyic converter on the car. Someone has replaced it with a strait pipe. I'll get that delt with later. After taking to muffler shop to make sure that something didn't get messed up when that was done the mechanic said after looking over the car that there is def a vac leak. So I started poking around and discovered that the air filter cover is all busted down the side. there is a chunk that would complete the seal around it. I have a new one ordered online. In the mean time, Autozone helped me put a seal around it temp. once it dries we will see if that helps with the RPMs. Here's to hoping it was that simple!

**Update**

Found the leak! It was the hose that goes into the bottom of the Mass airflow sensor. It was dry rotted and cracking on both ends. Car is running back to normal again

YAY!!!

[MetroMPG]

Nice! Thanks for letting us know what it was. Often people forget to update the thread to say "problem solved!"