1 series MOT emissions fail

[bmwcelica]

Hello, hoping to get some advice, my car just failed with these two faults:

001 Exhaust emissions carbon monoxide content after 2nd fast idle excessive [7.3.D.3]
002 Exhaust emissions lambda reading after 2nd fast idle outside specified limits [7.3.D.3]

Will have to take the car for diagnostics but the garage thought I will probably need a new cat converter

See attached image with breakdown of MOT emissions results:



Any thoughts please on what will be needed to fix this? Anyone had the same issue?

[E30M3SE]

You're running rich, could he a whole host of reasons why this is the case, I certainly wouldn't just throw a cat at it. Get it properly diagnosed by some that knows what they're doing.

Edited by E30M3SE on Monday 16th April 10:10

[dhutch]

Sounds daft, but have you or the garage checked for air leaks in the exhaust?

Saying that, my previous colleague had a 1series and was having issues with the flexi section welded to the cat. Garage wanted to replace the lot obviously, but he was in the process of finding somewhere that would cut out the flexi and welded in a new of the shelf flex section. Common issue I think.

Daniel

[SebringMan]

An air leak in the exhaust would cause it to look leaner, not richer, which is what the Lambda is implying.

With it looking richer I'd definitely get the codes read, preferably on a BMW scanner like INPA. My bet would be on one of the following:

-One of the O2 sensors, probably the first
-Coolant temperature sensor; what temperature does your car go to normally on the temperature gauge?
-Spark Plugs. Unlikely, but I've noticed the N52 has a stupidly long interval for replacement of the spark plugs, 100,000 miles to be exact. My friend's were completely shot by 60k.

Another thing to bear in mind is the test should only be done when the car is warm. It even warns the MOT testers when they look it up on the screen.