Questions and Answers

Hyundai Accent DTC P1128 Q. Mr. Ciulla, I have a DTC P1128 or P1148 with the Check Engine Light on. Would you please tell me what is the problem and the possible solution to it. I will appreciate. My car is a: 2000 Hyundai Accent L 1.5 liter DOHC L-4 Manual transmission 75,000 miles Thanks, Best Regards, William

A. It must be P1128 since there is no DTC P1148.

DTC P1128 is "Long Term Fuel Trim Too Lean". Which means the air/fuel mixture is leaner than the HO2S can compensate for.

This is most often caused by a vacuum leak. It can also be caused by a clogged fuel filter, unmetered air entering the air intake system, leaking exhaust system, canister purge system not operating or a weak fuel pump.