Try creating an exhaust leak- - - - -loosen the down pipe at the manifold, or remove the muffler, or drill a hole in the pipe ahead of the muffler, etc. One thing most people don't look for is a clogged exhaust system. I've found mufflers packed solid with rodent nests, collapsed double-wall pipes, and on newer vehicles, catalytic converters clogged solid with carbonized oil from a worn out engine that consumes a lot of oil. A sure sign of a clogged exhaust is intake manifold vacuum that drops to virtually nothing as soon as any load is put on the engine.
Jerry
Excellent idea. I've seen the same thing before. Fire an engine up and blow huge mice nests out the tailpipe if you're lucky.
I'll give it a shot. Thanks.
