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Hi all, I'm hoping someone can shed some light on my dilemma.
The nightmare started when I bought the car and the salesman assured me the Check Engine Light
was off and it passed smog. Well as the story goes he lied, and the check engine light came on
half way home from the dealership.
If I told you all the codes and repairs I've done for the past 3 years you wouldn't believe me, but it all
started with a bad Catalytic Converter which I replaced not once but twice because the 1st one
didn't meet Cal emission standards.
The second major issue was the previous owner had Helicoils to repair the head that were leaking
so I had to replace that . Along with 2 bad O2Sensors and a MAS sensor and MAS harness,
I also replaced all ignition coils, plugs and replaced the injectors with OEM refurbished ones.
And lastly I replaced a cracked manifold with all new gaskets and seals.
After all this, after driving 100 miles thinking I nailed it, I'm getting a P0300 pending code that won't
go away and a P0132.
I've done a smoke test and saw a little smoke (very little) coming from the intake manifold so I replaced
the intake manifold gaskets and cleaned out the EGR orifice hole on the manifold. And drove it again for
a hundred miles and got the same pending code P0300 and after driving it another 20 miles the check engine
light came on with the P0132. I checked all the wiring to the upstream o2 sensor and all seams to be working
as the wiring diagram and confirmed YouTube videos on signal voltage, ground, positive for heater and the
ecm ground.
If anyone has any idea on any tests I should perform that would be great. I just ordered a professional Oscilloscope
and have a pretty decent Launch OB2 scanner that's bidirectional and reads live data.
When the threads strip in a head or fail to hold pressure between the head and the spark plug, some mechanics recommend inserting Helicoils that replace the threads with a temporary fix. Regarding p0132 code my apologies its actually p0133 O2 Sensor Circuit Slow Response. So my question is, could this issue cause my P0300 random misfire code?
Ok, so it sounds like you're saying the spark plug threads were repaired twice? The spark plugs would not thread into the cylinder head and were leaking compression?
I've seen Helicoils in all kinds of places, I was thinking it was the threads for the actual head bolts that were stripped. The ones that hold the cylinder head to the block. If that were the case, I would be worried about proper head gasket sealing.
I don't think the B1-S1 oxygen sensor slow response is causing your p0300 random misfire code. For right now, I'm still more worried about the extent of damage / repairs that were made to they cylinder head. Some engines are more prone than others to spitting out spark plugs, I don't think I have even seen it on a GM I4.
There is a fair amount of drilling involved to use a helicoil, was this repair made with the head on the engine? Did all the drilling debris get into the cylinders? Do the spark plugs have the proper reach into the combustion chamber now, and do they also seal well?
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