Hmmm, good question. Start the truck, and put your hand over the exhaust pipe to see if the exhaust is getting good flow. If it's not, then your cat is clogged. I don't know why it would only run bad intermitently though. One thing you could try before spending money is to remove the cat, drive a hole through it with a pipe, and stick it back on. Fire it up and see if it runs any better, if not , at least you didn't lose anything.
|