So, I’ve done all that I can to fix the issue except,

• change o2 sensors
• crankshaft position sensor
• compression test
•coil packs

I’ve been dealing with this random misfire for awhile now. I’ve done a full tune up, fuel pump, filter, spark plugs and wires, all upper intake and head gaskets because I also keep getting low on coolant every so often. I’ve tested the fuel regulator. Everything I can think of other than what I had already listed and nothing seems to change. I had a noticeable difference after servicing everything but the misfires don’t go away .. cracked block ? I’m lost 3.8l , not swapping looking for help !?!?!?

 

take the egr out and see if its clogged up or stuck. check coil packs wire connections to make sure they are clean and getting contact. this code really sucks to figure out. any other codes?

 

P0300, P0171 are the two codes I can’t get rid of, I’ll check the egr next and hope I’ve checked everything off my list after tht why am I losing coolant but no visible leaks , after warning her up she smells like nothing but burning coolant no smoke . 🤷🏻‍♂️

 

There are a lot of things that can cause this. You made no mention of plugs, wires and fuel filter, also fuel pressure. If you clear the codes how long to they reset? do they reset at the same time?

You also should check some of the sensor values like Coolant temp and intake vacuum. After all that you may need to look at the MAF sensor and start looking at connectors.

 

how did you do head gaskets without doing the lower intake gasket. lower intake is a common fail for coolant. gorn he has replaced plugs, plug wires, fuel filter and fuel pump. please list all things you have replaced.

 

I never said I didn’t do those gaskets in fact I believe I said I did complete doing those reread my thread please and don’t doubt knowledge jus offer help


MAF, IAT, ALL GASKETS from head gaskets to upper and lower intake gaskets ., Spark plugs and wires , camshaft position sensor ,I’ve had vats removed and new ignition switch installed for previous reasons, as well as alternator and starter , radiator , diff trans and all other fluids except clutch fluid, fuel pump and fuel filter like I said before .. those plastic bypass elbows I switched to the aluminum ones , I’ve done all that I can think and I’m stumped , only things left for me to do are the o2 sensors . maybe the cat is clogged 🤷🏻‍♂️

 

wow, pretty much rebuild. I had a loss of coolant and found it by moving hoses when system was pressured up. one of the hoses was dripping just a little when I move the hose. cut end off and replaced clamp and was good. the leak was so slow that the coolant was not dripping off the motor and was not leaking except when system was pressurized and I guess when engine was running, maybe when engine was at higher rpms. check in the passenger side floor for any coolant also the drain hole for the heat/ac under car on passenger side. heater core may be failing. all I can think of.

 

Turns out my catalytic converter is toast and has been clogged up so I’m going to replace that right away and hope she’s good .

 

keep any eye on the muffler, sometimes the cat goes to pieces and plugs up the muffler. if there's pieces in it most times they will rattle when you give them a good bump.