2007 Accord...4 cyl...167,000 miles and never had issues before.....Just changed air filter which was HEAVILY CAKED in grime. Very surprised it could breathe at all !!

Put PREMIUM GAS IN TANK (2/3 FULL) and a bottle of FUEL INJECTOR CLEANER.

After one day of sporadic/normal city driving, the check engine light came on with code: P0240 ....and was told it's a common code indicating a possible catalytic system malfunction plus other symptoms.

Do you think the NEW AIR FILTER, PREMIUM GAS, and FUEL INJECTOR CLEANER could have triggered a faulty code display or "tricked" the system into generating the P0240 code??

Thanks!!!....and yes, the air filter was literally caked in grime and dirt. Never seen one so badly clogged!!

Mike

 

I recently had the same code after a long road trip. Ive been rehabilitating a neglected 06 v6 6spd sedan. just clear your codes, dont be afraid to get the cat hot and clean it up a little. Yes the filthy filter could have caused poor ignition and sooted up the engine and cats. clean your Oxygen sensors with brake cleaner and a light brushing or just replace them.

 

167K miles.

Are you still on the stock O2 sensors? Cause if you are, sounds like you may need to replace them.

Buy them cheap online, change them yourself. $200 total for both, only 30 minutes to change. ******