Whenever I have to come to an abrupt stop my car's idle gets A LOT rougher. It still seems to run ok, it ran the times in my sig about 3/4 weeks ago. It didn't do this then though. So, it could not be running ok, WOT feels fine though. I do have an exhaust leak at both sides of my y-pipe and headers, I don't think that'd cause this though. Anyone got any ideas? I'm thinking TPS or IAC?

Edit: After I brake hard and notice the rough idle, I can put in nuetral and rev a little bit(2k) and it'll go away.

 

My car has been running that way. Im waiting for my new 02 sensors to come in. I'll let you know if this fixes the problem. I has always thought that they were suppost to be replaced when they go bad. But I know now that you shouldnt keep them no longer then 50k on them. Well I have 80k on mine.

 

Check your oil pressure! Mine did that exact same thing, and it looks like the oil pick-up tube is messed up.

Read about it here.

Fred

 

Did your oil pressure do anything weird? My oil pressure is perfect WOT and after braking it isn't shaky at idle and around 20ish no matter what. Forgot to add, I haven't touch anything to mess up the oil pick up. Just headers and changing the oil, but I can't rule it out. Thanks!

I might change the o2s, that sounds like a good place to start considering I have 90k. I don't know if they're the original ones though. I just dropped money onto a stall though, so it might have to wait. Does running rich affect the o2s in a negative way at all, will it shorten their life?

 

did ur car ever stall after a really hard stop,.......same thing happens to me but not a lot.........one time it stalled one me...did it ever happen to u ?

 

Never dies, ever. It'll just idle real rough like it wants to die, but it won't. Like I said, just a little rev in nuetral and it goes away. That's what blows my mind. I forgot to add, I think my fuel pump could be the problem too, starts aren't as easy as they used to be. Takes a few cranks.

 

I'm an M6 and under extreme braking I as well notice a weird idle. Not really rough (cam kinda takes care of that) but different. I assume it has to do with the enormous amounts of vacuum it uses to brake. Probably nothing serious to worry about. I have noticed it in other cars that I drive as well.

 

Try replacing the EGR, it worked for me. After every, well to say it more accurately for me "abrupt." Try making a fast stop from over 30 and then make one from UNDER 30. If it only does it above thirty, then EGR will most likely be the case, since the EGR system is only active above 30.

 

What EGR?

 

Whenever I'd go to a hard stop, my oil pressure disappeared; zip, zero, nada. I'd give it a quick rev and it would pick back up. If I did a gradual stop, the pressure would stay the same. The engine would buck when the pressure was dropping, and that's what I saw as similarities in your situation.

The big difference, I think, is that my engine was apart this winter, and the pick-up probably didn't get put back on properly.

Fred

 

Gotcha, I'll check but I don't think that's it. It didn't really start until it started actually getting hot this summer IE 80+.

 

Well **** nevermind... but it did work for me!

Did you mean summer?

 

Yeah, I'm in 2nd grade.

 

dont want to hijack.......but.......

this also happens to me but not when im braking hard while driving, it happened to me a month ago while checking my brakes for any leaks. i was with my car in park at idle and i braked hard once or twice and the car sounded like it wanted to die, just gave it a little gas and it was back to normal idle. dont know if that is normal but i hope this never happens to me while im driving and have to slam the brakes in an emergency.

 

sounds like you have some sort of vacuum leak...