Check engine light keeps comming on

moswtr_178607
Wed, 30 Aug 2023 22:19:32 +0000
Maintenance/Repairs

A 1999 Suburban K1500, the check engine light continues to come on, especially when under-load like going up a 2000 foot grade. The DTC Code is P0304. The distributor cap and rotor and plug wires have been replaced and all new plugs installed. Te engine runs smooth with no hesitation. Fuel injector cleaner has been in the gas tank for five months. The light never comes on during in-town driving only highway. The engine runs fine, smooth, no hesitation or misfires. The local shop has not been able to find the cause. The code does not clear on its own, has to be done with a code reader.

4 posts - 4 participants