dub.ya.es.SICK

iTrader: (3)

ok I got full exhaust and a lid and85mm delphi maf, and ported tb. from like 4500 to 6000(I barely take it there now, the noise scares me.) it is a horrid rattling noise, I havnt had it tuned yet but I assume its knock or detonating...can I fix this? it happens more in hot weather. also how would I retard my timing, to fix it.....is my motor firing to hot? i gap mine at .055 how can I fix this without a tune.....98 ws6 m6.

rich Z

If you have the stock maf then put it back in. I had a z06 maf and it made my car runs extremely lean. Enough to eventully give a lean code. Another cause is carbon buildup. Get a catch can to slowdown oil from making its way into the intake and top of the pistons, valves. Then do a seafoam treatment to clean the carbon out.

TunedPower

Log the A/F ratios, throttle position, rpms, ambient temperature and total spark advance (and compare to some stock baseline) to see if your mods are causing the PCM to run to lean and/or too much timing for given conditions.