1999 GMC Suburban stutter

1999 GMC SUBURBAN
180,000 MILES • V8 • 2WD • AUTOMATIC
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SAINTDEER
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1999 Suburban. put in shop, fuel pump, filter, new battery, tranny serviced. When I am going up hill the vehicle slips like its not getting fuel. had both tranny and injectors looked at but both are said to be fine. put new air filter on also. Cannot tell if it is transmission or not. had aproblem with a visor light sticking on and draining battery right before all of this. When tran was serviced it ran great for about 4 days, then going up hill engine light came on and seems to be getting worse, then does fine again.....
Mar 28, 2009 at 2:08 PM
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MERLIN2021
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If engine light comes on or has come on and is now out, have it scanned, PCM will have freeze frame data stored to point us in the right direction, this is your first step, Autozone will read the codes for free, and may be able to scan the freeze frame data, not sure...write down all codes, and FF Data and post it.
Mar 28, 2009 at 7:29 PM
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SAINTDEER
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Light went off again, I got tested and catalytic code came up. So either catalytic converter or fuel sensor? I found a cheap universal cat. converter from eastern for 50 bucks, should I try that first or what, or is there still a way to drill out old cataqytic converter to see if that is the problem or not?
Apr 6, 2009 at 7:52 AM
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MERLIN2021
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Been hearing any rattling in the exhuast? The bed may have broken up, or melted. Bang on the cat with a rubber mallett, any rattles? You can test for clogged exhaust by using a vacuum gauge. Plug it in to a vac port, raise rpm's to about 1500, then watch the gauge, it should remain steady and 18-22 hg of mercury. if it drops, the exhaust is clogged. With a truck cat, you need one designed for it...too small and it will only reproduce the results you have now!
Apr 8, 2009 at 6:50 AM