Cole

Head was totally rebuilt just a few years ago. Upgraded valves, springs, ported, polished, o-ringed and shaved. (I'd have to dig out the paperwork to remember exactly what compression it was shaved to, etc) At the same time a new timing belt and water pump was installed and a fresh set of lifters.

A fresher set of injectors was installed, new vacuum hoses and fittings, new plugs wires, new cap/rotor. Exhaust is custom from the header back. Tial 38MM wastegate, Magnaflow cat back, new cat. Running old Huntley Racing chips, but the car has always run well on them so no need to change them. MBC, piston style BPV.

Car sits most of the time but my wife does daily drive it in the summer for a 40 mile round trip to work 5 days a week.

I haven't had time to do any checking on any of the suggestions. I appreciate them but I'm elbow deep in a timing chain job on a Eurovan. So I'm piling up the suggestions so that I can dive into the 951 next.

Cole

Thanks for all the suggestions. I drove the car for the last couple of days and 95% of the time it's running exactly as it should.

Occasionally and randomly I get the "gassy exhaust smell" and that is when it starts to stumble in second. Maybe a randomly sticky waste gate bleeding off pressure?

Aso tossed some sea foam in the fuel to see if that helps at all.

Rogue_Ant

Are you still running the AFM? I've had AFMs stick... Coolant temp, and wiring can also cause issues.

Cole

Yeah, still on the AFM.