I have a LS obd1 ecu with a chip that suppose to let me raise the limitor to 8500. Now, when I try to rev pass 6000 it feels like a rev limit and the neddle jumps back and forth and I can't go pass it. No codes either and when I try to put back a stock ls ecu it's still the same. What could be the cause?

 

limp mode check for codes.

 

I would double check that the ecu has been chipped because I know that had the same problem that you are having and the ecu chip wasn't burned right and he had it switched free of charge. Or it could be a interal engine problem that won't let it rev that high but with no engine codes it is hard to say.

 

wat kind of intern can there be? I have no cel or anything. I bought the car used and it had an aftermarket dial but I was hitting pass 6K before. I use to be obd2 but I changed to obd1. I tried the stock ecu and it still did the same... can my tach be off by a 1K rpm?