Exhaust Fumes In Festy

[dalebwilson]

I would probably vote for a donut connector leak, and possibly a clogged catalytic converter.
My old '88 did that too-
I seemed to get some result just running a lot of carb cleaner- like a 12 oz bottle a tank-

keeps the gunk out of the exhaust manifold and I think even keeps the catalytic converter screen from clogging-

if you have a catalytic converter, you may want to replace that or get it replaced with a straight pipe
I've replaced them- ordered the part first and had it installed
and looking through it, it looked like not much more than a small resonator with a little piece of screen door inside

that screen door eventually gets covered with carbon- and I seriously don't see what running exhaust through it does
especially anything that may require ANOTHER O2 sensor-

all pretty much a scam to sell us parts I think.

I did pull the cat saturday to look for leaks. It has already been gutted. I installed a new muffler, reassembled everything, pressurized the sytem and can find no leaks. I also replaced the thermostat which was stuck open and causing a cold running, rich engine condition. This appears to have helped some. My gas mileage has improved substantially and the temp needle is now in the normal range.