[jonobro]

Just today the check engine light came on and I ran tests using ISTA and got these

118001 - Mixture control mixture too lean

180001 - Catalytic Converter efficiency below limit value

I have Cp, dp, m performance exhaust with bm3 stage 1

[NinetyEight740]

Catalytic converters effeciency- you took yours out so yes you will have that fault.

Mixture control too lean- you still need to smoke test your intake to find the leak since you installed your charge pipe.

[ezaircon4jc]

Originally Posted by NinetyEight740

Catalytic converters effeciency- you took yours out so yes you will have that fault.

Mixture control too lean- you still need to smoke test your intake to find the leak since you installed your charge pipe.

I would think the gutted cat would throw the lean code too...

[jonobro]

Originally Posted by NinetyEight740

Catalytic converters effeciency- you took yours out so yes you will have that fault.

Mixture control too lean- you still need to smoke test your intake to find the leak since you installed your charge pipe.

I didn't take mine out ?

[NinetyEight740]

Originally Posted by jonobro

I didn't take mine out ?

You put in a catless downpipe did you Not?

[jonobro]

Originally Posted by NinetyEight740

You put in a catless downpipe did you Not?

Yes

[NinetyEight740]

Originally Posted by jonobro

Yes

Then you have no cat converter, that’s why you would have a catalytic converter efficiency fault

[jonobro]

Originally Posted by NinetyEight740

Then you have no cat converter, that’s why you would have a catalytic converter efficiency fault

So I don't have a leak ?

[John H.]

Originally Posted by jonobro

So I don't have a leak ?

Not likely. Your ECU is leaning out fuel mixture because O2s picking up above avg. HCs.

What precautions did you take? O2 bung extenders? Turn off O2s? You can't expect to bolt on a catless DP and expect nothing to happen???

[jonobro]

Originally Posted by John H.

Not likely. Your ECU is leaning out fuel mixture because O2s picking up above avg. HCs.

What precautions did you take? O2 bung extenders? Turn off O2s? You can't expect to bolt on a catless DP and expect nothing to happen???

What do you recommend I do ?

[John H.]

Originally Posted by jonobro

What do you recommend I do ?

Have you considered a tune? Based on reviews, Mission Performance seems hard to beat.

https://missiontuning.com/bmw-engine...are-flash.html

Post your query in the Cali section. I'm sure a local member/s will make other suggestions.

[jonobro]

Originally Posted by John H.

Have you considered a tune? Based on reviews, Mission Performance seems hard to beat.

https://missiontuning.com/bmw-engine...are-flash.html

Post your query in the Cali section. I'm sure a local member/s will make other suggestions.

I have a tune bm3 stage 1

[John H.]

Originally Posted by jonobro

I have a tune bm3 stage 1

My bad, for some reason, I thought you had a piggyback.

I am not familiar with BM3; however, there should be options to address the CEL issue.

[jonobro]

Originally Posted by John H.

My bad, for some reason, I thought you had a piggyback.

I am not familiar with BM3; however, there should be options to address the CEL issue.

I did so I'm not sure why I still have a check engine light and go those codes maybe I should get my car smoked to see if I have any leaks my local shop wants $130

[John H.]

Originally Posted by jonobro

I did so I'm not sure why I still have a check engine light and go those codes maybe I should get my car smoked to see if I have any leaks my local shop wants $130

That's about right. Get someone that is familiar with BMW.

I've been talking with another local via PM. Hit up jtrejo. He might be able to help with your diagnosis.

Have a good one.