holy crap my 95 s10 started running bad and missing and here are the trouble codes i pulled

p0300
p0172
p0141
p0401
p0441
what the?

 

The P0300 and P0172 codes (random misfire & fuel system rich) may be caused by a fuel leak inside the intake. The CPI engines are notorious for leaks inside the engine. Test the fuel pressure with a gauge attached to the fuel pressure test port located at the back of the intake.

P0141 means that the down stream O2 sensor heater has a problem. This could be a problem with the sensor or in the wiring. I would swap the sensor with the upstream sensor and see if the code changes. If it doesn't, then the sensor wasn't the problem and you need to start checking the wiring & grounds. If it does, then the sensor was the problem.

P0401 means that the EGR flow rate is not sufficient for what the PCM thinks it should be. This could be due to a malfunctioning EGR valve or a completely plugged valve.

P0441 means that the PCM detected an incorrect purge flow. This could be caused by a problem with the vent solenoid or the purge solenoid.

 

thanks!
so i need to reseal the intake?
and my downstream o2 was unplugged- 1 down 3 to go