So I have a 2001 S4. Only engine mods done to it are BOVs (dont ask why).

So at random times, my car decides to buck and sometimes even stall itself. It happens at low speed/rpm. (too scared to go highway speeds) Sometime I try to smooth it out by stepping on the gas some. and that does work. But sometimes when ASB ESP lights turn on, it just goes downhill from there...

I have a few theories, possibly BOV not closing? Computer issues....
But I know its not leaking vacuum lines
The S4 isn't throwing any CEL's or codes at the moment

I need some help. Any ideas will be appreciated. Thank you


12/13
I have a bad MAF. getting a new piece in by the end of the week. could that cause this?

 

Put new DVs on it and throw the BOVs in the f'n garbage.
The system needs to be closed a circuit.

That, will fix it!

 

The rings on one or more of your axles are broken, usually the rear ones. Mine where bad and the car would do the same thing. They are the litthe rings that abs sensors detect as the wheel spins. If u wanna know which one it is, pull the abs sensor (one by one) look through the hole of the sensor while turning the rotor and see if the ring is damage or broken. Ussual from rust. Hope this helps.

P.S the bucking you feel is the abs kicking in thinking the wheels are slipping so it tries to slow em down.

 

If this is the case, then simply turning off the ESP with the button should prevent this from happening, thus proving that is what's wrong with it.

 

This actually just happened to me yesterday on my way home. Its freezing out here and I shifted from 1st to 2nd and my car bucked pretty good which then flashed the ABS and ESP lights.

Had no problem getting home (roughly 25 more miles) and drove it to work fine today.

So what exactly needs to be fixed to cure this problem?

My front CV boots have been worn down for a while now and I was planning on replacing with rebuilt axles anyway. My question would be what needs to be done for the rear then?

 

i turned esp off, and it still does it. i have a bad maf. but i dont think it could cause these problems. some cel's came out as major misfires and low circuit maf readings. could the maf be the heart of these problems? i thought it could be ignition issues, so i swapped out all plugs. but issue still continue.

 

Replace the MAF.

 

on it