Nissan Altima p0300 p0420

Question

I have a 2002 nissan altima 2.5s and I've been having a problems with the check engine light coming on. It started about 3 months ago I had a Misfire in Cylinder 2 so my mechanic changed the coil and the light stayed off for a couple days. When it cake back on it came in for code P0300, so I had all the coils and spark plugs replaced. Well my car started like bucking when I'm accelerating and my SES light starts to flash and goes off. Well last night It stayed on so I went and got it scanned and the codes were P0300 and P0420. And idea? The car runs amazing when I'm at idle just when I hit the gas it sucks?? Please help

Answer 1

Hi there,

I would suggest removing the front O2 sensor and test driving the car. With the P0420 code it's possible that the catalytic converter is plugged up. This will cause the exhaust pressure to back up and can cause the multiple misfire codes. Most often the car will idle fine but under load die out.