I wanted to know if anyone has used catalytic converter cleaner? I saw advertised at auto parts stores for cleaning out the system including the dirty or clogged cats? Just trying to see what can be tried before changing one or two cats. I have the P0420 and P0430 codes on a ‘02 XLS Explorer.
@9COOP5
I've been fighting the CEL with repeating "HO2S Heater Resistance Bank 1 Pos 2 for about a year. Vehicle runs perfectly. At first, assuming heater resistance was the culprit, I checked the heater resistance. Within specs, all 4. Replaced all 4 sensors, same code. Ripped out all Bank 1 Sensor 2 wiring from fuse to sensor, sensor to PCM, replaced with new wiring. Same code. I heard these heater codes were used to alert to cat converter problems. Finally, desperate, I bought some of that expensive crap which is "guaranteed" to clean cats. No effect. Tried it again, almost a hundred bucks gone; it's bullshit.
So, I resolved the cat at least RH side must be replaced. Took a close look: The nuts on the studs at the exhaust manifolds are rusted away so badly, there's no corners left on them. Ditto at the other end of the H pipe, biut those could be sawed off. Runs perfect, fuel usage OK, I have let it slide, screw the CEL, but check it now and then to make sure no new very dire codes have come up. 164k on the vehicle, 4.0L 2004. I've even considered reverting the EFI system to OBD-I, using 4.9L 6-cyl. PCM, using only one O2 sensor. Big headaches to pull that off, transmission shifting (do not know of a stand-alone controller for 5R55S, entire instrument panel inoperative, fuel gasuge, speedo, not to mention very finicky ABS, etc. Thought about running TWO PCMs, one for engine only, but not certain if one disables so much, the '04 might shut me down. Then, there's the Throttle Body, need changeout to non-drive by wire, install cable & pedal, and fuel pressure change, spark advance curve, on and on.........imp