MX-3.com

I have a leak in my exhaust where it goes to the cat. My idle jumps from 750 down to like 500. Anyone know if this would cause that? I have checked all of my vaccum hoses/connections. Its fine while driving down the road, but if its in neutral it sounds like its putting.....
thanks in advance.

no your exhaust shouldn't effect this at all. Check all the vacuum lines over again and then reset your TPS, rubber hose from the throttle body to the MAF and if that doesnt work. Take a little propane tank and turn it on(don't light it!) around the intake runner and the throttle body while the engine is running, if the idle jumps higher then you have a leak somewhere.

Exhaust leaks can definitely affect idle/power/mileage - remember O2 sensor is measuring O2 in exhaust gas stream - if the gas stream is diluted due to leaks or backdrafts of air (before the cat) then o2 sensor will have the wrong readings making the computer dump fuel.

However rule out vacuum leaks first....

If the leak is after the 02's it will not affect the idle. There are only 2 o2's on the 92 model both are before the
cat.
I would start with a good old fashioned tune up. spark plugs,cap & rotor, check for vacuum leaks,check timing
and TPS voltage.

Andy P.

I have the same problem i still yet to check vacum lines but from the looks of things it doesnt look like its that btw my mechanic told me to change the fuel filter that might be causing the problem im not too shure on that but my car does run a bit rought when i accelerate it hesatates and studders a little bit whats TPS?

TPS = Throttle position sensor.

I doubt the fuel filter is the problem, plus its a pain in the behind to replace.
Spark plug wires could be the cause of your acceleration problem.
Make sure you don't have a split in the intake accordian tube.
The TPS shouldn't cause a studder in your acceleration. if no one's messed
with it then its probably still in the right spot.

Andy P.

How old is the cat? if it is pluged up it will affect performance, idle, gas millage...

cat is really rusty im guessing ill have to replace it too i just spent 500 on a new cat back exhaust stock ofcorse. I the main reason why my mechanic said it was the fuel filter is because this is a 2 owner car im the 3rd the previous owner was a lady and she used it as a summer car so it wassunt maintained on time it only has 177 original clicks and when i got it i had 1 quater tank and i drove it till it ran out because i was compleatly broke at that moment and thats when the studdering started were thinking all the crap in the gas tank got sucked up n clogged the filter but as soon as i filled it all the way to the top and put in some injector cleaner the problem went away now it only does it sometimes usualy when i jurk the car.

Thanks for the reply i will take what you say into consideration if the fuel filter doesnt fix the problem

Don't know when this post was made, but...

An Update on your situation?

Its running fine now i changed the fuel filter thanks a lot for the help guys!

Still haven't figured out what my problem is. I have checked all my plugs, and they are all good, checked my firing order. Going to get the exhaust fixed on friday. Will repost if this helps or not.