99 venture backfire

[cbr600rrnut]

Hi gang

So over the last while after runnning at highway speeds 110-130kph for approx 50kms I would pull off the highway and after sitting at a red light the engine would hesitate and pop (backfire) for about 2-3 seconds and then clean up and run normal. Sometimes the cel would come on only if I run speeds over 120kph and then goes off approx 100km later. Scan code P0101. Now this morning I was driving to work at 110kph and the engine lost power and will backfire if I step on the accelerator to increase speed. Now if I step down hard to engage the downshift the engine will accelerate normally. I am thinking possibly a plugges cataletic converter? MAF? Any thoughts?

Thanks in advance

[merc81]

Not the catalytic converter; if it were plugged you would never get anywhere. Sounds like the MAF and that's what the code is for. Take it out and look it over. Could be all you need to do is clean it up.

[rockwood84]

could be the fuelpump also as some of g.m.'s fuelpumps do not die all at once. or die a quick death. they will start by pumping a while then backflow then pump again. when they backflow then the engine is starved for fuel and the engine backfires. one other thing is the tps sensor and them good ole cheap intake gaskets do not like the concusion of a backfire. you will end up putting a tps sensor in and if it backfires much you will end up putting intake gaskets in also.put a fuel pressure gauge on the fuel line and see if the fuelpump will hold around 50 pounds steady pressure. but i'm betting it will drop to around 20 pounds or so and then the backfiring will start if you give it gas .my fuelpump actually took close to a month to die it would pump 50 pounds pressure for a while then drop down to 10 pounds then back up.

[cbr600rrnut]

I cleaned the MAF sensor and all has been good...so fat at least..lol.