96 3.1 V6 hesitation only when warm

[travis4chauncey]

Can someone please help. I have a 96 Lumina with 3.1 V6. Runs strong first thing in the morning, but as soon as it warms up after 3-10 minutes, it starting hesitating. If I floor the gas pedal, it quits hesitating, but shifts very hard or very late. I have done a tranny service, ran injector cleaner through it, and replaced the plugs (it had Bosch Platinums). I have also checked the EGR. The car only does it if I ease the throttle down slowly. I am very stumped by this one.

Thanks for any help,

Trav

[travis4chauncey]

I have figured it out. For anyone that has the same problems, replace the catylatic converter. I dropped the exhaust and looked inside the cat with a flash light and it was plugged. So I knocked all the honey comb out of it and now it runs like a champ, better than when I first bought it.

[carking527]

Yo thanx for the info, i had the same problem. At low RPM's the car would hesitate when hot, sometimes stall. I think my problem is a combination of the fuel pump regulator, fuel filter and the catalytic converter prob you mentioned. I'm also gonna try some injector cleaner and maybe some top cylinder lubricant. Thanx again, keep rollin'.

[The Burning Rom]

For those living in cities that have emissions testing, do not do what travis4chauncey did. It is highly illegal.

[RABarrett]

Aftermarket cats are typically the monolithic type, which reduces exhaust backpressure. The pellet type works fine if intact. I agree; do not simply remove the cat. Have it replaced. The new one, by design, has less backpressure. Ray