What should I first expect a mechanic to look for to help diagnose the problem. It already has had a diagnostics test and no faults shoed up. I know there is defo a problem when I go into limp mode I already paid for it to be looked at but the limp mode keeps coming back on. The catalytic converter has been welded and does need replaced would that be enough to affect any sensors that could cause it to go into limp???
My car has 63106 miles.
My car has an automatic transmission.
Hello. Thank you for writing in. If the catalytic converter has failed then this was absolutely cause the engine to enter into limp mode. The engine cannot breathe so to speak, and it pushes what they call "back pressure" into the engine. There are sensors that can detect this and will cause the engine to slow down. If you already know that the catalytic converter needs to be changed, then you will want to start there. If the problem continues after you’ve changed catalytic converter then you can continue with further diagnostics.
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