Hi, hopefully someone can help figure out what's going on here! I have a stock 98 Cobra, just Flowmasters and K&N. I took it in for a chip and custom dyno tuning a few weeks ago only to find that it's pinging too much to be tuned. I was disappointed to find it's only putting down 248RWHP.
It's pinged for a long time and the only thing that seems to help is to put a couple gallons of 100 octane unleaded in the tank. I've replaced the fuel pump (it actually died awhile back), the coil packs, plug wires, spark plugs, MAF sensor and all the fuel injectors. The guy doing the tune told me there's no trouble codes, O2 sensors are working fine and suggested that I replace the whole exhaust system. Occasionally, I get a sulphuric smell when I drive it hard as if the cats are overworked. Periodically, I get a rough idle as if the engine is straining to run, but after driving it, this clears right up. I've even replaced vacuum hoses and checked for leaks and everything looks good. So my question is.... do you guys think the exhaust system could be causing this ping, and is there anything else you can think of to check? Any input on this is welcome! Thanks.
