hi new guy ... need some advice

[mitch01]

i recently bought a max.01 .. 75k miles .. drives fine and great ses light on got 2 codes .. cat sys. effiency below threshold bank1 and o2sensor circuit high voltage bank 1 sensor 2 changed sensor and cleared codes ..light came back on ......my question is wat is the fastest and most effective way to resolve this problem

[Murdered_T]

New frontpipe, they go bad a lot.

[Murdered_T]

Its the big pipe that looks like a snake with two triangle plates where it mounts to the exhaust manifolds. It has a bradded pipe near the end of it.

[allensteiner]

looks like you have a bad oxygen sensor. replace that, clear the codes and you should be fine.

[mitch01]

thks for the qik responce ....i changed the bank1 sensor 2 (rear02 sensor) and had my mec clear the codes but it came back earlier today . .... wat is my next step and again thks 4 the in fo

[mitch01]

thks 4 the qik response .....do u think it would b easier to do a y pipe instead with the stock cat and again thks 4 the info .

[loystock]

Are you sure the mechanic replaced the correct O2 sensor? In 01 Maxima, the Bank 1 sensor 2 is mounted on the precat. Also, the O2 sensor is very sensitive and can be damaged when mishandled or dropped

Rod.
Modified by loystock at 10:40 PM 6/23/2009

[allensteiner]

your cat might be shot or just gunked up too. if you're not already - running premium gas might help. also check out the fsm for o2 sensor troubleshooting: http://www.nicoclub.com/FSM/maxima/2001/could it be that your mechanic replaced the wrong o2 sesnor?