Volvo 855T popping during deceleration

Post by **bmdubya1198** » 25 Jun 2018, 17:15

I had a strange feeling it would come back...

If the O2 sensor code is still present, I'd definitely replace it. A bad O2 sensor could surely cause a problem with how the car runs.

henrysin44 · Post by **henrysin44** » 25 Jun 2018, 17:52

bmdubya1198 wrote: 25 Jun 2018, 17:15 I had a strange feeling it would come back...

If the O2 sensor code is still present, I'd definitely replace it. A bad O2 sensor could surely cause a problem with how the car runs.

Me too, Volvos love to make you think you've fixed the problem, though it has to be either the MAF or the O2 or both. They're the only sensors I haven't replaced, plus I noticed I was boosting 2psi more than usual.

Post by **bmdubya1198** » 25 Jun 2018, 18:01

Maybe the O2 sensor or MAF is what's been causing my car's stutter. It was running like crap today... stumbled on acceleration at least 4-5 times, rather than its usual stumble when I'm stopped.

henrysin44 · Post by **henrysin44** » 26 Jun 2018, 15:25

bmdubya1198 wrote: 25 Jun 2018, 18:01 Maybe the O2 sensor or MAF is what's been causing my car's stutter. It was running like crap today... stumbled on acceleration at least 4-5 times, rather than its usual stumble when I'm stopped.

Ok so I swapped the MAF no difference, I pulled OBD I codes from under the hood to find I have 1-1-2 on A2 which is ECU failure, when I tuned my ECU I applied 12V to the wrong pins at one point and just assuming that probably killed it. Good thing I hid a M4.4 ECU at the scrapyard!

Post by **Clemens** » 26 Jun 2018, 16:16

This all is the universe punishing you for running no cat...
Or maybe not.

Post by **bmdubya1198** » 26 Jun 2018, 17:58

henrysin44 wrote: 26 Jun 2018, 15:25 Good thing I hid a M4.4 ECU at the scrapyard!

So I'm not the only one who does that!

Post by **RickHaleParker** » 26 Jun 2018, 18:20

K&N gets the extra power by reducing the filtering capability. In other words it reduces the intake airflow resistance by allowing larger and more particles to pass. The particles are like sand in the engine, they increase wear and tear on the engine.

If you want to reduce the intake air flow resistance, use a filter with more surface area but the same filtering capability as OEM. You just need to figure out how to mod the setup to accept the bigger filter.

Post by **bmdubya1198** » 26 Jun 2018, 19:02

Yeah, that’s why I’ve always been skeptical about those filters. I figured I would give it another chance and see how I like it on my R.

Post by **RickHaleParker** » 26 Jun 2018, 19:22

You might like K&N until your rings and cylinder walls wear out prematurely ....

Post by **bmdubya1198** » 26 Jun 2018, 21:59

RickHaleParker wrote: 26 Jun 2018, 19:22 You might like K&N until your rings and cylinder walls wear out prematurely ....

After doing a little reading I might throw it on eBay. I went back to the Mann in my daily, might as well throw one in the R too.
My initial reasoning made sense... how more flow could you really get without letting in too much dirt?

K&N seems to be similar to Fram... they can sell like hot cakes, and they have no motivation to make a better product for that reason.