just swapped the stock y pipe to the intercooler and the small one going from ic to inlet mani with autobahn ones. i reset the ecu by leaving the battery disconnected while doing it. Took it for a spin and after about 5 mins the check engine light come on, i checked the fault code when i got home and its 22 knock sensor. its never give out that fault code before and all ive done is changed the y pipe any ideas why this would happen?

 

forgot to mention its a 98 uk turbo 2000

 

I believe the knock sensor is right below the intercooler. Check you haven't snagged the wire. They commonly crack and give up as well. They don't cost too much from eBay.

 

cheers, think it was cus i forgot to put one of the interooler bolts back in, reset the ecu again once both intercooler bolts were in securely and no more cels , still getting a rough idle though goes between 500-800rpms gonna try cleaning the idle control valve today, i noticed one of the bolts was missing out of it i could only see 3 so that could be it, or it could be my hks ssqv

 

I've heard hks valves can cause idle problems too, I have a turbosmart BOV and it doesn't cause any issues. I don't know if the problem is directly related to hks?? Also, vent to air valves aren't really that good if the car is using the MAF sensor.

I'm going MAFless with my ESL ECU soon