Hi,

I have a stock Canadian spec 2008 Manual Fit Sport with ~240k km on it. I've been getting an intermittent MIL with accompanying P0420 code. Of course this is a strong indication that the cat is bad, but I'm wondering if it's worth throwing O2 sensor(s) at it first.

I've been using Torque Pro to pull codes and monitor various engine functions. I get a good reading for the Bank 1 Sensor 2 oxygen sensor, but it doesn't list any available data for Bank 1 Sensor 1. Is this normal, and Torque simply can't access that data? Or is this perhaps an indication that the pre-cat sensor is faulty and not reporting to the ECU? I would expect it to throw other codes if it wasn't reporting at all, but I'm new to all this OBD2 stuff (I come from the e28 world).

Thanks in advance!

 

you should have bank 1 both sensors I think,, i'll check when I get home.. As I recall mine shows bank 1 occupied both sensors an bank 2 missing both..

 

Any word on this?

I talked to a few other guys that said a P0420 code is 99% a cat problem, so I think I'll be buying one in any case.

Anyone had any luck with the magnaflow? Or is this a case of Honda OEM or bust?

 

Because the car is a SULEV the tolerance on the cat is tiny,, like stupid tiny.. When I had the same code I ran through our Emissions test station, the exhaust was < 2% out of spec. I ran 4 tanks of fuel through it with a 1/2 can of sea-foam per tank, the cat temperatures jumped about 400 degrees on the freeway, it quit setting the code. Mine had a crack in the down pipe that I think caused the ECU to over fuel and it fouled the cat and the O2. My theory is the sea-foam cleaned all that out, once the pipe was repaired and I ran the cleaner haven't had a code in a couple months.