Developed rough Idle several weeks ago. Replaced defective cat with no improvement. Noticed a hiss coming from what I beleaved was the flame trap. Replacing flame trap and hoses did not improve idle. Tried to isolate the leak listening with a fuel line hose. The leak seems to be in front of the flame trap between 3&4 cylinders intake. Spraying carb. cleaner in this area smooths out the idle but makes the greatest difference between the intakes, not around the observable portion of the intake gaskets. It also races slightly when started. Am I missing something here. The intake gasket seems to be the most likely culprit. If so what are the issues involved in replacing it and how much would a mechanic be expected to charge.

Probably less than an hour for a good mechanic. Plus a few bucks for the gasket. Might not hurt to replace the oil separator while you're at it.

If you have tools, it's not that hard to DIY this one. 8 nuts hold the manifold on, and you'll just have to loosen a few other things to slide the manifold off a couple inches.

-Ryan
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Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars
1991 745 GL 295k, Regina, 23/21mm Turbo Sway Bars
Buckeye Volvo Club