low idle/stutter

Hey guys,

Installed a cheapo intake on my 2001 Corolla LE. Now, with the 1zzfe there are two sensors that need to be attached. 1 via the vaccum hose that is included in the kit and 2 the O2 sensor (?) attached to the pipe. In an extraordinary display of impatience while I went inside to get a flat head screwdriver, my friend attached the O2 sensor but completely stripped one of the bolts. He mounted the sensor on crooked so unfortunately there isn't a good seal between the sensor and the intake pipe. I'm gonna have to drill out the screw and replace it. I temporarily taped up the gap between the sensor and pipe, but would that gap have anything to do with my lower idle/stutter? I now idle at about 450-500 rpm, not 650+ like before.

Thanks,
ROKnight

I don't think O2 sensors are found in the intake, they belong in the exhaust, so it's probably the IAT (inlet air temp) sensor. This should not cause any problem if it is before the throttle body even if it was in the free air.

Your problem is possibly a vacuum leak -- this will cause idle problems if it is behind the throttle blade, but not if it is ahead of it. I'd use some liquid Steel or RTV to make sure that the intake is not vented by the stripped threads.

Now, if all of this is happening before the throttle body, I would put the stock intake back on because your issue also sounds like a restricted intake issue...

Get any "check engine" indications? Sensors and their wiring are easily damaged by "impatience." :)

that sensor is actually a MAF(mass air flow) sensor...it tells the computer how much air is passing through and how much gas it would need to put for the right air:fuel ratio...so that might be the problem if it is sticking out a little becuase it would be reading too much air than what is actually going into the engine...

Ok, update...

used a socket wrench and removed the mounting stud, plier'd out the stripped bolt and reseated/replaced new bolt. So there is now a good seal on the MAF sensor to the intake piping. The idle is still a little rough, steady though. The car actually shakes/vibrates when the car is in drive, but the brake is being pressed (i.e. at a stop sign).

FYI, I would put my stock intake back in but my sober (yes, sober) friend ran into a pole with my car on New Year's.... the pole was 1 foot away from where the car was parked. In wrecking it, he completely shattered my stock resonator and intake piping....

ROKnight

Without knowing the exact CAI you have it's hard to tell if you have a problem or not -- aftermarket intakes allow more air -- that sometimes means that more air than the idle circuit is used to may be allowed in [maybe the PCM needs to re-learn it's adaptive tuning?] -- it's certainly going to be more noisy under the hood under all conditions.

The shaking may just be a result of the engine breathing better :)