Changed my opti 2yrs/5000 miles ago and did the air box mod, k&n filter, TB air foil and coolant bypass. I've got a 94 auto. About a year ago the head gasket went and had the heads redone + ported, and new injectors (24#). Started having an issue at idle where my oil pressure (10w-40) would drop to ~5psi once warm and drops even lower when it pops, sporadic popping that increases as the car warms up, no smoke or amything from exhaust, fluctuating rpm from 400-600, voltage bounces from 14.4 to 13.8 and the lights dim slightly, startup sometimes sputters but always starts up. Thought it was an exhaust problem so I got new EM headers and a full 2.5 in straightpiped exhaust, balanced w/ X pipe, New o2 sensors, New plugs and wires, removed AIR and EGR. The popping and idle issue is still present. The popping goes away when I drive but highway driving at 2k rpm consistantly feels spotty. High rpm feels and sounds fine. Fuel pressure is at 42psi and all cylinders passed a pressure test. Ive checked for vacuum leaks, unplugged wires, leaking fuel...nothing. So I have a few theories but would love your feedback. 1. I'm running lean due to better flowing exhaust and more air in but not enough fuel 2. Optispark has gone bad...again.... 3. Ignition coil is bad (I only think this because it's the only thing I haven't replaced ignition wise) 4. My tune from garrettuning needs to be redone since it was done before all these exhaust modifications. 5. My valves are either put on incorrectly/ too tight/ too loose. I ordered an aldl to usb cable to run software to check the engine out but based on my description what do you all think my issue is?

 

K&N Filters can be trouble if over oiled. The oil can damage MAF. I would install a standard air filter and attempt to clean MAF. You could unplug MAF and see how it acts. Did opti get wet during head gasket repair? Cap and rotor are available separately, rotor screws should be loc tited in place. If rocker arm adjustment is too tight you can get backfiring out intake or exhaust depending on which are out of adjustment and vacuum will be lower than it should be. Beyond that you need a scanner/data logger

 

I've honestly never oiled the filter in about 2 years of having it so doubt it's that. I'll try taking out the MAF tomorrow and seeing how it runs. I sent the car to a local shop for the head gaskets so I don't know if they got coolant on the opti or not. I've already replaced it once so I'm saving opti swap as a last resort. Aside from the MAF I'm gonna retorq all the rocker arms and make sure they're to spec. I've got an aldl to usb cable coming this week hopefully I'll be able to see on my laptop where my issue is. Fingers crossed it's not the opti