KOOL!!! Thanx Doc...It never dawned on me to do a vacuum test on the engine to test for low exhaust flow!
That's why your the 'Doc'!
| > Thanks, | >
| > John Manner | > 4.3L 4x4 | > 1989 S10 Blazer | | With the engine hot, at idle, in park, hook up a vacuum gauge to one of the | TB vacuum ports. Should have between 17-22in/hg. Tweak the throttle a few | times. Vacuum should drop 2in/hg then pop right back to where it was at | idle. Next, hold the throttle at 2k rpm for 5 seconds, then 3k rpm for 5 | seconds. Vacuum shouldn't budge more than 2in/hg from the idle marker. If | it doesm this indicates resistance/backpressure in exhaust and likely a | plugged cat. | | Doc | | >
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