denis_the_thief

Hope someone has advice

I've had a smell inside the car, it's noticeable when idle or diving slow. I believe it's exhaust. And the check Engine light is on - code p1273.

I went to a mechanic, they replaced an O2 sensor. But after driving 15 km, the light came back on. The smell never went away.

2 questions:
1. since the smell is inside does that imply there must be an exhaust leak?
2. is it possible the mechanic was wrong to replace the O2 sensor? i.e. if it is a leak, the O2 sensor did it's job by raising the code. His original explanation was that the car was running rich, that's why the smell and the engine code was there. though I'm wondering if it was both the sensor was bad and there is a leak.

My concern is that I paid a lot to get the O2 sensor replaced and the problem is still there. And possibly the mechanic will guess wrong again if I bring it back.

Tarzan

1. Yes
2. Yes

eaterofbirds

P1273

https://www.autocodes.com/p1273_nissan.html

Seems someone just went at it without performing a true diag

denis_the_thief

Thank you both!

They looked at it again (no charge, at least). They think the smell is burning oil. And the Engine light is from a cracked catalytic converter. If true, replacing the O2 sensor was likely a waste, and it's an expensive part. So I don't think I'll go back there, except for installing tires maybe.

But I have to admit: my oil change is overdue. I'm going to try that today. And hope that reduces or eliminates the burning smell. I don't think it will fix the engine light, but maybe it will...

eaterofbirds

Oil change and check engine are unrelated. Unfortunately, some shops go for the throat when it comes to diag.
An minor oil leak is more a nuiscance than anything...you could do worse by learning the ins and outs of routine maintenance and a set of ramps and getting under there to look around. Getting to know your car is pretty important, especially with these cut throat type of upsell shops just preying on the unsuspecting.

denis_the_thief

Another place looked at it and they also said the catalytic converter needs to be replaced, the rear one. But they quoted the part as being very expensive ($500). I phoned an Auto Parts place, they suggested going with a universal catalytic converter, it's price was way cheaper (70$).

Any opinions on going with a Universal Catalytic Converter?

Tarzan

How did they come to that conclusion? Did you fail emissions?

denis_the_thief

Yes, I failed the emissions, but prior to that, there were fumes or something entering inside, seems to have gotten a little worse. So, they did some diagnostic and they noticed a hole/crack in the rear catalytic converter.

Tarzan

I used to have Magnaflow main cat and it was fine and inexpensive compared with OEM.

denis_the_thief

Thanks! I'm thinking to get that done...

denis_the_thief

Sorry for slow to update. The Cats were replaced, not cheap no doubt. And then I passed the emissions.

The smell inside the cabin is less now, but there still is some.

I was wondering if changing the cabin air filter would help? Otherwise is there some way to seal the car so that smells/exhaust don't come inside and bother/harm the passengers?

Tarzan

it won't help. burnt oil smell smell is not dust or pollen, it's gaseous and will pass through the filtering element. you need to figure if there is oil dripping onto a Y pipe or cats, or there is an exhaust leak under the hood. Nissan's VQ35DE is known for oil pan rust and cracked valve covers, check those out.

Les7311

The down pipe w catalytic converter on a 2010 Altima had a leak and stwalership wanted $1200 to do the job. Found partnon eBay new for $450 and did the install in buddy car.

Get the part number and go check eBay or amazon. Do the surgery yourself .... not hard.

Les7311

Here’s what you may need and the fix