Rep Power: 0

My main question is if my engine is misfiring on all 4 cylinders is it possible for a bad MAP sensor to be my problem and if so can a perfectly fine brand new cat. Go bad from oct1 to now? I have had my spark plugs, alternator, ignition rotor, distributor cap, and catalytic converter replaced since Oct 1 now the cat is bad again. Nd my check engine light is still on. (also my idle is so horrible my car shuts off everytime I stop so my friend slightly adjusted my base idle so the car stops cutting off) nd now the car is reving on its own when it's started and I'm not even touching the gas.(could my iacv be the problem instead of the MAP sensor?)

 
Rep Power: 188

Try cleaning the MAP sensor, IACV can cause idle problems yes...

1. what Code is your engine light giving you.
2. What is going on with the car..i got rough idle and stalling..that it?
3. How do you know your cat is bad?

The function of the IACV a.k.a. Idle Air Control Valve is to adjust the idle based upon the amount of air entering the engine, then the computer reacts to this information by adjusting the cars rpm.

Reasons why you should take it apart and clean it:
-High idle after your car warms up
-Lumpy idle
-Roaming idle
-Hunting idle
-Fluctuating idle

Tools Needed:
Ratchet
12mm Socket
Pliers
Brake Cleaner or Simple Green
Paper Towels
A cooled down engine for at least 2 hours

1) Now you got to locate where the IACV is, pop your hood and it’s located directly behind the intake manifold. It’s actually connected to it. Remove your intake and strut tower bar. (If applicable)





2) Place a couple of rags underneath to catch the coolant spill. Loosen the two hoses running to the IACV with your pliers by squeezing the two clips and moving them away from the end, circled in yellow. DO NOT cut the hoses as they are the exact length and you will have to buy new ones if you do.

3) After doing that remove the harness connected to the IACV on the driver side, circle in blue.

4) Then to finally remove it from the intake manifold, remove the two 12mm bolts, circled in red.



Now that the IACV is removed from the intake manifold make sure that you do not lose the rubber gasket as you need this so that it does not leak after you re-install the IACV.

5) Take your brake cleaner or simple green and start to clean up the inside of the IACV by spray inside the two holes. Continue to do this until no more dirty fluid comes out. Should take anywhere from 5 minutes to 15 minutes. This depending on how old and dirty your IACV is. The gasket can be seen in this picture as well.



6) Once you’re done cleaning out the IACV let it air dry. I let it air out for 20 minutes while I did other maintenance on the car.

Now your ready to re-install it back on the car so follow the steps backwards from 5 – 2

 
Rep Power: 0

How do I clean the map sensor?
Yes rough idle and stalling was my only two problems but now the car won't let me accelerate past 25-30mph and it's started getting a little hot so I stopped driving before it over heated but this happened out of now where and there was a hissing noise as well. I'm assuming it's the cat because it has a bad rattle and I'm having the same problems I was having before I got it replaced the first time

 
Rep Power: 0

Codes are p0420 and p1509