Please Help No passing gear ??????

First the fuel pump went out over the weekend . I had it towed home this morning and dropped the tank put in the new pump . When I started it up it idled rough a few min and smoked then went to normal. I took it down the road and when I hit the gas in any gear it just revs up and stalls but still runs . If I dont push the gas very hard at all it will go through all the gears . Any help is appreciated.:banghead: oh yea its a 96 tahoe 2wd 5.7 auto

I found where it could be a clogged cat . is there anyway to check this first ???

First the fuel pump went out over the weekend . I had it towed home this morning and dropped the tank put in the new pump . When I started it up it idled rough a few min and smoked then went to normal. I took it down the road and when I hit the gas in any gear it just revs up and stalls but still runs . If I dont push the gas very hard at all it will go through all the gears . Any help is appreciated.:banghead: oh yea its a 96 tahoe 2wd 5.7 auto

I found where it could be a clogged cat . is there anyway to check this first ???

Does the transmission slip or engine RPM flare up.
Or does the engine just bog down.
Quick easy fast test.
To check for restricted cat check vacuum at idle and at 2K RPM.
If vacuum dropes when engine speed up you have a restricted exhaust system.
A exhaust shop or repair shop can also test back pressure for you.

ok thanks bro . it feels like the trans sticks at the speed its at when it trys to go into passing gear the engine just revs up smoothly but no more speed . ill try that out in the morning though would i just check the vacuum at the brake booster line?