[cormac827]

So I recently put in new (to me) throttle body....that fixed my RPM fluctuation issue at a speed around 40-55! wweeeeee

but it drove fine for about 40 miles, and now on the way to work this morning, it seemed to be misfiring/stalling slightly while I am accelerating on highway.

It did it several times, but I kept going. it is a 95 YJ auto 2.5l, has an exhaust leak that I need to fix, 186k.

What could this be? some kind of vacuum leak or should i look for something else?

Also, The Check Engine light came on, it was not on before, when they Throttle body was messed up. IT could be due to exhaust leak i suppose, im not sure. I tried the turn key on off trick and failed.

let me know what you think!

[rustywrangler]

First off I would try the key trick again: OBDI Error/Check Engine Codes - JeepForum.com Community Jeep Wiki

Second, I would definatly bet that your exaust issue is the problem now. I had the cat and muffler go on my 90 2.5 and she threw codes out the wazzo and would not run right. Replace the exaust and she ran fine.

I also would not rule out a vac leak BUT you just said you have an exaust leak so it could be either. Run the codes again and see what ya get.

[cormac827]

yep. I will try code trick again. thanks!

i think replacing the gasket on the header is too much for me, the bolt was finger loose! i could barely get ratchet in there to tighten it, but i did. So I am guessing repalcing gasket would be tough. Ill see what I can figure out.

I will try code trick after work today most likely. I will try replacing muffler, and maybe tailpipe and see if that helps too.

[idaholtby]

Originally Posted by rustywrangler

First off I would try the key trick again: OBDI Error/Check Engine Codes - JeepForum.com Community Jeep Wiki

Second, I would defiantly bet that your exhaust issue is the problem now. I had the cat and muffler go on my 90 2.5 and she threw codes out the wazzo and would not run right. Replace the exhaust and she ran fine.

I also would not rule out a vac leak BUT you just said you have an exhaust leak so it could be either. Run the codes again and see what ya get.

I agree... Check your codes, they will help to pinpoint the problem. An exhaust leak can allow air to get sucked into the exhaust and cause the O2 sensor to believe the mixture is too lean which in turn will cause the ECM to dump more fuel in to compensate. So check your codes and fix the leak.

[cormac827]

hmmm......that sounds like it could be it, probably causing it to stall out shortly. Idk, ill look into the exhaust, hopefully I can fix it for not too much (BROKE!!!)....

hmmm. I wish this happened Friday so I had all weekend to work on it. frustrating! Once I get chance to do codes, I will report back.

[Que89YJ]

If you just replaced the throttle body you might want to check for a vacuum leak and recheck the torque on all the nuts and bolts. The nuts and bolts tend to loosen after you heat them up for the first time so you might be looking at something simple. Also, do the starter fluid thing to check for the vacuum leak. The exuast will cause the O2 sensor fauklt to blow, but so will vacuum leaks. Check that harness to the O2 sensor too. Its close to the exhaust and can get trapped and short real easy.

[cormac827]

okay thanks. Where do I spray starter fluid to check for the vacuum leaks?

[Que89YJ]

Spray it around your intake mainfold, throttle body, and all the vacuum lines. Listen for an idle change. Do it outdoors, the either can be dangerous. Also do it in short shots. Mores law does not apply to either!

[cormac827]

either? is it ether? I dont have a garage, so itll be outside. Ill go buy some started fluid after work. First I will check those bolts though haha, thanks!

[bigbelman2009]

you can do the same thing with brake cleaner

[cormac827]

Thanks... I checked codes and got ac fault(no ac), memory temp erased(disconnected battery.) and last one was , throttle positioning (something, maybe circuit?) out of circuit I believe. So something wrong with one of sensors on tb? Hmmmm idk. Haha. No exhaust codes I don't believe.

[bigbelman2009]

the tps needs to be adjusted when one is put on, its not a plug and play sensor

[grnjp88]

Throttle position sensor, perhaps?

[cormac827]

yeahh..."throttle position circuit out of range".....I am not sure. I replaced the throttle position sensor, but i just put it on, and then put new throttle body on....

How do you "adjust" it, i am very unfamiliar...In the meantime I will search forum a lil bit too!

[prussell]

I have had my jeep for about 6 weeks and it has started to make a high pitch continuous chirping sound when using the accelerator. This high pitch noise happens while in all 5 gears. As soon as I lift off the pedal, the noise goes away. The noise is not there when in neutral or reverse. This is hard for me to diagnose since I must be going forward using the accelerator. Maybe related, but this started happening after receiving a lot of rain in the past week.

’94 YJ 98,000 miles; 4.0 Manual; 33x12.50x15; 4.56; 6” lift; Tom Wood shaft with SYE and rear Detroit Lockers.