Hi there in need of some ideas of possible cause for a servere misfire at any revs on a MY94 WRX Mods: TSL down pipe, HKS centre + back box, walbro fuel pump, bosch coilpacks, magnacore leads, trust spark plugs and K&N panel filter

I have replaced the coil packs for bosch coilpacks(group buy ones) + new magnacore leads and new plugs a couple of months back and everything was running better than ever then last week out of nowhere a permenant misfire occured!
So this evening checked plug gaps- ok, checked power at coilpacks-ok, plugs were quite sooty tho...?

My thoughts: MAF faliure or Lambda faliure..??(the one in the headers)

Where on the net can i get a lambda sensor from...?

Please any help would be greatful...?
Jon

 

You need to go back to basics and try to establish which piston the misfire is on then try to swap plugs or leads to see if fault is still there. If problem is still there then need to check maybe for fuel. If both spark and fuel are ok then it might be timing.
It is highly unlikely that a lambda sensor is causing the misfire.

Maybe it might be best to take it to an expert, as so often self-instant diagnosis can run up a big bill from replacement parts when an expert can often diagnose in an instant - thus saving time and money.

Thanks
Gavin