while coasting in neutral, my car dies. i replaced throttle positioning sensor and it helped but it still does it every once in awhile.. when it does die it throws it in limp mode. any ideas what it is?

 

if its in "limp" mode you probably have a CEL

check it (its in the faq)

my car used to do this, it was bent valves, it could also be a vacuum leak, map sensor, IACV

does your car rev up and down at idle?

and what kind of car is it? that helps alot as well

 

it's a 00 civic si with a gsr swap. also I'm running a rywire harness and I'm unable to read the codes.. it doesn't idle up and down at idle.

 

Why?

 

I'm not sure. iv tried different code scanners. none will read it. i think it has to do with that everything obd2 except it's all ran into obd1.. I'm not sure

 

Pull the codes by jumping the service connector. Click the CEL sticky at the top.