Originally Posted by
pizzaguy
One more thing, fuel pressure is NOT measured in our cars. The ECU assumes you have about 55psi at all times and runs the injectors based on that pressure. If your pressure is low, the ECM won't know that.
Fuel pumps and fuel pressure regulators can become intermittent and erratic. Fuel trim values and O2 values will be out of whack but maybe not enough to set a code.
The only way to know is to test or even full-time monitor fuel pressure. If you can catch it when the engine is not running right, check fuel pressure, if it is not within a few pounds of 55psi, FIX THAT!
I like this kit, it is almost as easy to measure fuel pressure as tire pressure (tho fuel pressure is a potentially dangerous thing to measure, as fuel at 50 psi will spray if you are not careful!):
https://www.summitracing.com/parts/otc-5630
Ok so when I first got the car 10 codes one of them was the following for an O2 sensor. I have not replaced those yet due to i do still need to replace wires and plugs., and fuel filter. So maybe once I get these replaced it will be better. Maybe not sure 🤔
