HKS_IS300

i turned on my car today and the check engine light came on and the trac off light came off. i was wondering if i could narrow down the problem. any help would be much appreciated. thanks!

GRAND_LS 4

iTrader: (2)

Will since you dont want to tell us the year, and miles, the only thing I can tell you is to use the search function.

HKS_IS300

my car is a 91 w/ 209k

lorenzo816

TROUBLECODES

lp_yang

i have the same problem now too......still aint figure it out....

HKS_IS300

what's weird is that it went away.....i still want to get it diagnosed tho

persian451

most likely O2 sensors. do the self diagnosis using a paper clip. cant remember which pins again, but do a search. The flashing codes on the speed cluster will tell you which sensor.

justfixit

Look under hood for the Diagnostic Connector located on front driver side of engine. Jump terminals E1 - TE1. If you look under the cap of connector it will diagram terminal locations.
If light comes on and off frequently it is most likely code 25 or 71.
Code 25 is Oxygen sensor but you will have to diagnose which one. You will need voltmeter, set to check volts, one lead to E1 and the other lead to
OX1 (bank #1) and then OX2 (bank #2). If you rev engine quickly and let off you should have a reading of .1 to .9 volts and it should change constantly. If you dont see any voltage change then that is the defective sensor.
Code 71 is for insufficient EGR gas temp. Usually this is due to leaking vacuum modulator for EGR or EGR passages clogged.
Good luck