Hey guys. A few days ago I noticed that the idle was hanging around 1000 rpm instead of coming down to around 800. Checked around for vacuum leaks and couldn't find any. I noticed that most of the time if I tap the gas it will come down to around 800. Sometimes if I wait about 10 seconds it will come down to 800 on it's own. Doesn't matter if the engine is hot or cold- raining or sunny. No check engine light. I have a scanner that shows live data if there's anything I should check on there. Thanks.

 

Think the O2 sensors could have anything to do with it? I put in new O2's when I put the longtubes on about around 7000 miles ago. They weren't AC Delco's though- they were Denso. Around the same time I replaced vacuum lines, put in a new IAC, cleaned TB, and replaced intake manifold gaskets. If I have time later today I'm going to hook up the scanner and see what it shows.

 

Double check the vacuum lines you replaced and intake bolts, vacuum leak could cause that. Codes would be a good next step. The IAC was the culprit when I had this problem.

 

Hooked the scanner up this morning and went for about a 15 mile drive. Must have scared it because rpm's came down and idled fine the whole time. All the sensors seem to be reading where they're supposed to. Going to leave the scanner in the car and wait for it to do it again.

 

Note what your IAC counts are at hot idle. If they are lower than 20, you might have a vacuum leak.

 

10-4 thanks. I remember they were 20 at point and 30 at another when hot sitting at traffic lights. I'm about to take off again for a longer drive so we'll see what happens.