davehoose
NAXJA Forum User
- Location
- watertown ny
Well, I've overposted but everytime I have a problem "fixed" it all comes back to the muffler. I have changed the precat 02 sensor fyi. My 89 4.0 aw4 seems to run great with the side blown out of the muffler. I change a few things, it runs great, I replace the muffler and it starts bucking and backfiring again. Which leads me back to the 02 sensor which I already changed. I also changed the air temperature sensor because it was clearly fried. I am thinking the map sensor, would this be off with a muffler installed? The thing runs great with no muffler, but as soon as I install one (I am on my fourth brand new one in as many months) it starts bucking and backfiring. It seems to be just as I am letting off the gas pedal or right around 2500 rpm which is 55 mph or right after a stop and I am just starting to accelerate. I cleaned the ground from the engine to the firewall and it ran great, getting almost 20 m.p.g. I ran like that for a week (no muffler because it blew up again) and did not want to hear the noise anymore so I put on a high flow muffler and bam! backfiring intermittently as well as bucking at cruising speeds. I am thinking map sensor as i've swapped most of the other sensors for new. any clues?
thanks for your time,
dave hoose
[email protected]
thanks for your time,
dave hoose
[email protected]