Put car on computer.

[Cavalier9696]

Went to Auto zone and had them put my 95 rs on there computer cause service light was on. Some said its because I run without a cat. So i just wanted to check. With amaze this is what came up.


Idle air control motor circuit
Problem cause
Open or short circuit condition
Poor electrical connection
Failed IAC valve

Heated oxygen sensor - bank 1 sensor 1 (ho2s11)
heated proformace
Problem caused
open or short circuit condition
Poor electrical connection
Faulty ho2s11 (bank sensor 1)

Timing belt skipped 1 tooth or more
Problem caused
Jumped timing belt
Loose camshaft or crankshaft position sensor


Wow..lol dont even know where to start. Me and my buddy rebuilt the engine and knew the timing was off. Have plans on fixing it this weekend. But the other 2 I am lost on.

[david-b]

Replacing the front O2 and the IAC is where you start.

Or test at least test out the IAC as shwon in the manual to make sure it is relly defective. If not, clean and reinstall.

[SilvrEclipse]

[Cavalier9696]

Originally Posted by david-b

Replacing the front O2 and the IAC is where you start.

Or test at least test out the IAC as shwon in the manual to make sure it is relly defective. If not, clean and reinstall.

Ya i was also told to try and clean the IAC to see if that helps before i spend any money. But would the IAC make the idle, lets say "crazy" cause the car pretty much idles good. I have idle set at 1000 and every now and then it goes to 1200 or falls to around 900. That normal?

And are we talking about the downstream O2 sensor? Cause i think it runs to the catalytic converter which I don't have. Or does it run to the exhuast manafold?

[david-b]

Bank 1 sensor 1 is the O2 right off the turbo in the O2 housing. I forget if your car is turbo or not. If not, it's in the downpipe.

And yes a bad/faulty/dirty IAC will make the car idle funny, considering that's its job, is to make the car idle properly. A bad O2 will also do the same

[SilvrEclipse]

Dave he has an RS. The O2 will be in the DP, replace it and see if the code goes away. It should be replaced every 100k if not before so Im sure it time for a new one. The IAC controls your idle so you cant 'set' your idle speed. The ECU is just going to adjust the IAC till it gets it back where it wants it. Some times codes will randomly get thrown and the sensor may still be good. Usually what I do it clear the codes and if it comes back then I start testing it to see if it needs to be replaced or not.

[Cavalier9696]

IM going to buy the OS thursday. On the trottle body there is a type of bolt that let me ajust the idle using a star wrench. Unless I ajusted the wrong thing, but it did change my idle from 1500 to 1000 after I bought the car. Sorry for all the questions or not understanding, still new to Mitsubishi.

[david-b]

Originally Posted by Cavalier9696

IM going to buy the OS thursday. On the trottle body there is a type of bolt that let me ajust the idle using a star wrench. Unless I ajusted the wrong thing, but it did change my idle from 1500 to 1000 after I bought the car. Sorry for all the questions or not understanding, still new to Mitsubishi.

That piece only adjusts where the butterfly plate rests at. Honestly, it does nothing since it's small enough changes that the ECU still compensates and adjusts. Also, if you look at the TB, the passage for the IAC is before the butterfly, so adjusting that doesn't actually make a difference. If you're idle was at 1500 to begin with, there's a bigger problem at hand.

[Cavalier9696]

Originally Posted by david-b

That piece only adjusts where the butterfly plate rests at. Honestly, it does nothing since it's small enough changes that the ECU still compensates and adjusts. Also, if you look at the TB, the passage for the IAC is before the butterfly, so adjusting that doesn't actually make a difference. If you're idle was at 1500 to begin with, there's a bigger problem at hand.

K thanks for the help guys. Once I replace them, I will update.

[SilvrEclipse]

Someone may have adjusted it before and set it wrong. Its only there to keep the throttle plate from going all the way back, if it wasn't there or adjusted right the throttle plate may stick a little bit

[Cavalier9696]

All problems worked out fine. Fixed the timing tonight, put a new o2 in yesterday. Getting new IAC tomorrow cause it was tested and was told to just buy a new one.

I put it on the computer and the only thing that was bad was the IAC. I can tell a differance after fixing the timing. Alot more pickup.

Thanx for all the help