checking online and couldnt find a definite answer. i have an 05 honda S2000 and im throwing 4 codes. P0172, P01441, P0420, P0410. i understand most of it is from my cat but i dont know what i need to replace. the car idles perfectly fine when cold but when i accelerate it studders like it looses compression or not enough fuel is going in the engine. there is still power in the engine but the studder is bugging me. i do have a straight pipe with an HKS exhaust and an intake. does anyone know why it studders and what i need to do to fix these codes???

and btw, my intake actually fell off after going over some train tracks slowely then driven for a couple miles and then i put the intake back on when i noticed. thats when the situation got worse.

 

P0420 is the cat, or you have a test pipe.

P0410 is an electrical failure in the air pump circuit. Possible fuses. (P0411 is air pump flow issue, like vac lines..this is NOT your code so vac lines are not it)

P0172 is the car is running rich. many causes.

P01441 is not a valid s2k code. Double check.

EDIT: I think you put an extra 4 in there P0141 is a bad 02 sensor in the cat. IF YOU HAVE A CAT in the car, make sure the cat material has not come loose and slid into the 02 sensor, breaking it. This is common.

 

These codes are from an AP1 so they may be different as I'm guessing yours would be an AP2 being a 2005? We only have the AP1 over here in the UK so I'm sure someone will clarify what I'm saying.

P0172 - Fuel System Too Rich
P0141 Secondary Heated Oxygen Sensor (Secondary HO2S) (Sensor 2) Heater Circuit Malfunction
P0420 Catalyst System Efficiency Below Threshold
P0410 Air Pump Circuit Malfunction


It sounds like something is going on that has killed your secondary 02 sensor in the exhaust. If there is over fuelling it could be the primary one gone as well and the cat could be dead as a result depending on how much over fuelling there is.

While you're at it, if your intake fell off then check all your VAC hoses in case something is disconnected.

You may also have crap in your MAP sensor or throttle butterfly so its worth giving it all a clean seeing as its an easy job. Take your intake off, clean out any dirt from the butterfly with some carb cleaner or other cleaner suitable for intake manifolds.

Then take your MAP sensor off the top of the throttle body and blow down the hole in the throttle body as well as the MAP sensor itself. Re-grease the O ring with some lithium grease and put back together.

It may not be 100% accurate but I hope it helps.



EDIT: Looks like Billman beat me to it! Secondary 02 sensor failure could mean its been killed due to running rich IMO, its a common one and hence why BERK do the CEL fix on their decat. I'm guessing you threw a CEL with all of those?