651Don

Not sure if my last post is being seen but will 93 ls400 run fine without rear o2s?

Yamae

It's only checking the performance of the catalytic converter and it doesn't affect the engine control loop. Without it, the car would run fine.

651Don

Could I possibly be having some kind of ECU issue?

Yamae

I can't say any definite answer without knowing the detail. How deep did you check your car?

651Don

We changed out most sensors, new spark plugs, fuel filter, maf, checked throttle body, checked for spark. I’m not too mechanically inclined so my buddy does most of the diagnosing. No check engine lights on, we did scan for codes but it was a few sensors that we changed and it didn’t fix it. A few people have said it’s the ecu but i’m hoping maybe someone here has had a similar issue with wide open throttle cut out.

Yamae

If electrolytic capacitors are all original Nichicon's P series, simply replace them unconditionally. They seldom last 3 decades.

651Don

Took apart the ecu about a month ago and they all looked brand new no visual leaks but would it be worth it to just replace them?

Yamae

Yes, it's a good idea to replace them. Capacitors can't be judged by human eyes. We need to use a capacitance and ESR meter or an impedance meter/analyzer to judge. Those infamous QAS capacitors should be replaced using newer low ESR capacitors listed here.