2000 Bravada sputters

[tlane276]

Been running great up til today. Now theres a rough sputter until i give it some gas and theres a slight ticking sound coming from the exhaust pipe. ive been told at 1 time that my heat shield may be loose. catalytic converter??

[mcmalloy]

could be a vacuum leak

[Chris Stewart]

I agree on checking the catalytic converter. If it's coming apart, the downstream O2 sensor will probably react to it and cause a fuel leanout which would result in the stumble....all help gratefully accepted.

[tlane276]

got underneath and looked. theres an exhaust leak(puffs of smoke) coming from a small hole in my muffler, just under where the tailpipe connects. at idle, the sputter is almost not noticable, only a little. It's worse right when I hit the gas a bit. After I get the rpms up a tad, it seems to get better. There's a definite shake involved too. If it is the cat conv, how hard is it to fix? any online step-by-steps??

[Chris Stewart]

Are there any additional leaks in the exhaust system?
I have a pal whose Northstar kinda acts that way without the noise.
It also turns on the Check Engine light. Is your Check Engine light on?
Buying some non-alky gasoline fixes his miss and turns off the check engine light.

[tlane276]

Originally Posted by Chris Stewart

Are there any additional leaks in the exhaust system?
I have a pal whose Northstar kinda acts that way without the noise.
It also turns on the Check Engine light. Is your Check Engine light on?
Buying some non-alky gasoline fixes his miss and turns off the check engine light.

Ah...a buddy came over and said hes almost positive its a fuel issue (i.e. clogged injectors, filter, bad gas) as opposed to exhaust. suggested same fix. i put a whole jug of stp fuel system cleaner in it and it ran alot better. friend told me to give it a couple treatments so i just put in sea foam at a coworkers urging. we'll see how that does. and YES...the check engine light is on. hasnt come off yet though. its the wifes truck and despite my pleadings, she runs the thing almost to empty every time. who knows what gunk she sucked through the system. im guessing that the improved performance after the fuel additives means my friend was right. Theres still a tiny roughness to the start(of course, im in minneapolis and its -5 this am) and a little shake right as i press the gas, but once the rpms are up just a tad, the shake goes away. it idles beautifully. next step???? should i wait til shes down on gas again and do 1 more treatment of fuel cleaner? does it sound like im on the right track and I can wait to pay for a diagnostic check? maybe give it a couple days and see if the light comes off?

[Chris Stewart]

I agree with you as the engine is running better.
You can get a free scan at most chain type auto parts stores.

[tlane276]

Originally Posted by Chris Stewart

I agree with you as the engine is running better.
You can get a free scan at most chain type auto parts stores.

I got a friend who works for Ford up here. He said to give it a couple days, watch for a loss in power and watch the check engine light. Shes about to 1/4 tank so as soon as she gets down to 1/8 or so, ill throw 1 more jug of fuel systen cleaner through it. Started alot better today. Still cold as heck so Im hopin some of that SeaFoam is workin its way through. Too bad about this truck. If it wasnt nickle and diming me the last couple years Id be very pleased w it. 2 weeks ago we had a blizzard. Woke up to 16" at the end of the driveway. The Honda was garage-bound for theday. But the 'Vada.....the 'Vada took me and the neighbor all the way to the beer store like it was driving on a regular road. She garnered respect that night.

[Chris Stewart]

You've already done the transfercase flush/blue Autotrac II haven't you?