Is this serious?

P0420

according to google There are a number of things that could be causing this p0420 catalyst efficiency code. The most common thing is the catalytic converter itself is no longer functioning properly. The other likely thing is the rear O2 (oxygen) sensor is no longer working properly. Other things could include exhaust leaks, damaged exhaust pipes, damaged O2 sensor wiring/connectors, plugged catalytic converter, etc. so it would pay to go see your local mechanic

I understand this issue has probably already been resolved by misssims456 since its been 4 months, BUT for any others who may be researching this problem, you absolutely must get it repaired immediately. Nissan put 2 catalytic converters in that car with an egr valve between the 2. If you don't get the problem fixed right away, you run the risk of having catalytic converter media (i.e. sand) sucked into your engine which will necessitate a new engine. And BTW, Nissan never issued a recall of that fatal design flaw for the engine. Loved the car otherwise & was sad to see it die.

Service engine light stays on in my 2003 Nissan Maxima Auto Zone trouble shooting codes are P1800 and P0021. Do you know mechanics that can fix problem. do not wan to take to dealer where cost is at least $400.00 Harvey

P011

I read a post about checking your gas cap, especially with an older car your cap seal might be worn out. Sure enough my cap wasn't tightened properly. I tightened it and the light went off after driving another 20 miles or so.

I had the same issue and I had inserted the key directly to car and that sensor is gone. The possible problem would be battery in you remote key might be low.

hello

I'm gettinv "Service engine soon" issue on my car is it a major problem ? I've nissan altime hybrid 2010

well I disconnected the battery and reconnected it and the light was gone....is this still serious or I should just ignore it?

Nissan Altima 2008, 126,000 miles. I bought it in dealer for diagnosed. Came back with code P0840. Need to replace transmission, Costs about 4000. I am shocked.

I have a 2009 altima had it fixed couple months ago and my engine lights back on ,after 60mph it shakes a lot today,at a red light it was gulting back and fourth it also sounded as if it was struggling to stay on any ideas I'm so scared just spent 3,000 at the dealers to have them turn on my car back in June

@Slimnflakita that's what's happening to my 2006 Altima right now, but it starts to jerk at 30mph . it's been to the mechanic twice already

@royalhighness I ended up getting a consumer affairs Case and took it back to a different Nissan dealership and it turns out it was the engine the Cadillac converter and the transmission,; ( good thing the dealer will cover my enigine replacement and Cadillac converter just not my transmission

My 2006 Altima was having issues misfiring (jerking) with blinking service engine light and ended up it was an ignition coil. That being said, light is on again but runs fine.

My service engine light came on today and my car smells like gas any ideas?

I just cleared mine by replacing the filthy air cleaner and on the third time driving the car, it cleared itself. Hope it helps someone!

I have a high idle around

check your gas cap my Altima check engine went off when I replaced the gas cap only cost me 20 dollars

I got same sign after I change oil and fuel tank was half after 2 days . I drove it 2 more days and made my gas tank full and tighten the gas cap . It went on its own :) Quick fix. If its still doesn't go you may have to show your local mechanic.

Nissan altima hybrid 2010 just got that Service Engine Soon MIL lamp ... can some one help me out what codes needs to check