I drive a 1997 Toyota Tacoma King Cab 4 cyl and 2.4 liter engine (180,000 miles). About 2 weeks ago my wife drove it and when she got home it was really loud. My neighbor (a 70 year old mechanic/ ex-owner of his own collision shop) looked at it and said that the pipe on the catalytic converter had broken where the manifold meet the converter. He welded a new pipe on and brought the truck to me. I then went to a home improvement store and on the way home the truck began to stall when it idled. For the rest of that day on it stalls when warm and idle. My neighbor looked at it again and couldn?t figure out what it was. I read about back pressure issues with a repaired catalytic and asked him to just replace the catalytic. He instead replaced the muffler. He said that he detached the back end of the catalytic and that it didn?t stall. So he thought it was from there back. So he changed the muffler. The problem persisted. So I (very handy but not knowledgeable about cars) decided to change the catalytic ? it is only four bolts and he had just loosened them. I replace the catalytic with an OEM direct fit and now it idles great while cool and warm if in park. But when it is warm and in gear and I go to accelerate it stalls. I have also cleaned out the throttle body (I think ? a thin cylinder that opens and closes with the accelerator) with carburetor cleaner. Even after cleaning the throttle it still stalls. Both O2 sensors were replaced about a year ago. I love this truck and I would like to put another 180,000 miles on it. Any ideas, comments, or suggestions?