(Solved) Excessive exhuast popping on decel all of a sudden.

[AWE46M3]

I'm kinda "in for the learning" here, so pardon my ignorance. Is *any* amount of popping unacceptable? OP you say "excessive". I have a little popping I guess--SSV1 catted kit, 63.5mm dual pipe resonated S2 and race muffler, HTE tune. I get a little off throttle popping, but barely. I have to pay attention to it I guess. But, drives great!?

Are you tuned for light pops/burbles? Saw Hassan has that service listed (light pops all the way up to gun shot sounds) on his E46 Tune package.

[bmwfnatic]

Could have screwed up the injectors by cleaning them. New Bosch injectors cost less than one BMW injector. Great time to put in bigger ones. You have think, injectors operate in milliseconds. They could be a little slow by a few milliseconds which doesn't completely cause an issue but they aren't closing like they should. It's the one things that was touched in a way that will really damage them so I'd start there.

Bosch injectors are NLA though...

[Arith2]

Could have screwed up the injectors by cleaning them. New Bosch injectors cost less than one BMW injector. Great time to put in bigger ones. You have think, injectors operate in milliseconds. They could be a little slow by a few milliseconds which doesn't completely cause an issue but they aren't closing like they should. It's the one things that was touched in a way that will really damage them so I'd start there.

[Riley]

For anyone following this thread. I installed another new o2 sensor on bank 2 thinking maybe the first replacement sensor was bad and smoked tested again but nothing changed. Flashed my car back to stock tune to see if it was tune related which it is not.

Once again no codes at all but getting excessive burble on deceleration. Only thing I am thinking now is use a wideband on the dyno to see if it afr shows rich or not.

[Riley]

I'm not sure, but when you clear adaptations doesn't that reset the cat monitors which then makes the monitors incomplete, then sets it to its default setting to run rich (safe)?
With your incomplete monitors and new o2 sensor your setup is now maybe running rich causing the unburnt fuel, so then shouldn't you do the drive cycle to have the cat monitors in a ready state for the o2 sensor to determine the correct mixture? Does that make sense?

Ive been driving the car for 2-3 weeks since swapping the sensor and setting monitors.

I just reset the monitors again by forcing a code to come on by unplugging a sensor while the car was running so i could clear the monitors. Going to try to do the drive cycle again now

[Riley]

What is MAF flow rate in g/s at hot idling? Over report MAF can cause rich mixture.

4.79 g/s hot idling

[Halftim3]

I'm not sure, but when you clear adaptations doesn't that reset the cat monitors which then makes the monitors incomplete, then sets it to its default setting to run rich (safe)?
With your incomplete monitors and new o2 sensor your setup is now maybe running rich causing the unburnt fuel, so then shouldn't you do the drive cycle to have the cat monitors in a ready state for the o2 sensor to determine the correct mixture? Does that make sense?

[Riley]

I'm kinda "in for the learning" here, so pardon my ignorance. Is *any* amount of popping unacceptable? OP you say "excessive". I have a little popping I guess--SSV1 catted kit, 63.5mm dual pipe resonated S2 and race muffler, HTE tune. I get a little off throttle popping, but barely. I have to pay attention to it I guess. But, drives great!?

When I mean excessive I mean excessive. Picture any newer bmw like a 335i with a straight burble tune. I get non stop popping as soon as I let off the throttle. I drove the car for over a year tuned this way and never had as much as a single pop on decel. Drives like normal other then the popping,

[Riley]

That means nothing, they can fail. Popping clearly indicates unburnt fuel, so check your live fuel trims.

Long term/short term fuel trims are normal. Not sure how I would monitor the trims live while driving without installing a wideband sensor?

[sapote]

What is MAF flow rate in g/s at hot idling? Over report MAF can cause rich mixture.

[PSUEng]

I'm kinda "in for the learning" here, so pardon my ignorance. Is *any* amount of popping unacceptable? OP you say "excessive". I have a little popping I guess--SSV1 catted kit, 63.5mm dual pipe resonated S2 and race muffler, HTE tune. I get a little off throttle popping, but barely. I have to pay attention to it I guess. But, drives great!?

[TexaZ3]

Injectors were just cleaned about 200 miles ago.
The report from the fuel injector place even showed they were nearly spotless before hand.

That means nothing, they can fail. Popping clearly indicates unburnt fuel, so check your live fuel trims.

[Riley]

Clear adaptations?

Already been done once.

[Riley]

Issue with injectors?

Injectors were just cleaned about 200 miles ago.
The report from the fuel injector place even showed they were nearly spotless before hand.

[bigjae46]

Clear adaptations?