VW Vortex - Volkswagen Forum banner

Rough idle when cold and warm helppp

1K views 6 replies 4 participants last post by  Wolfsburg-Tom 
#1 ·
So I have a 1.8t Jetta and just got stage 1 for it. Cars got stage 2 clutch and a staight pipe and I mean nothing but a pipe. Anyway after I got the tune my idle jumps up and down when I come to a stop when it's in neutral. When I push te clutch in the idle will even out and say like that but as soon as I let go back into neutral it will start jumping up and down. Only code I'm getting is p0030 bank 1 sensor 1 heater circuit. Which is the pre cat o2. Now could the o2 be causing the problem? When I clear it the code the idle problem goes away but soon comes back. My maf is not even 10000km old yet and we realigned the throttle body. That helped for a couple days then back to rough idle. So could it be the o2? Thanks in advance. And my cars been dumping fuel likes it's not getting the right air fuel mix.
 
#4 ·
Replaced 02 that helped a tiny bit but After a few days my car would bog up and down still when ever I came to a stop light. Putting it in gear would level it out but when ever I put the clutch in or came to a stop the cars idle would drop and even stall somtimes. When I get on the gas the car sometimes would sputter and bog. Am I in limp mode? Sometimes when I drive there's no boost other times when I start it up and drive it's on normal(stage 1) boost. Only code I'm getting is for the rear o2 sensor which is because I don't have one plugged in from running a test pipe. I've cleaned my maf and unplugged it and it ran worse so it's not that. Did the coolant temp sensor about 8 months ago so don't think it's that. Thinking it might be a dirty throttle body or a vac/boost leak. Was gunna seafoam it to to try and clean it up. Can anyone please give me some insight. Mabye even Crank Position Sensor or fuel relay/injector/filter? idk someone please point me in the right direction because I'm getting tired of fighting the idle when ever I come to a stop. Thank you!
 
#6 ·
They do have some sort of mode tho... I was having issues where I'd only boost apx. 6 lbs. I'd restart while driving and then I was able to fully boost again. I don't remember what the issue was, but I was able to find it and fix it.
I'm 02m also

Like Bond said, smoke it and or boost pressure test it.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top