2011 SOHC Ping/spark knock on 87

[Uncle Gump]

We’re going to make fun of you no matter what, admitting to your mistake will just make our job easier.

I say we just start making stuff up...

 

[PetroleumJunkie412]

Preface: I hate you all, except @alwaysFlOoReD and @adsm08. You two are cool.




So, turns out the MAF on my 2011 is crazy sensitive to literally anything, even air filter varieties.

After finding out that the AFE cone filter intake I picked up on fleabay was the wrong MAF housing size, I went to the junkyard and picked up another air box cover to hack into a homebrew cone air filter tube:

Stock MAF housing with an AFE filter and velocity stack. Thought it would work fine.

Nope. Ping and knock city.

So, I put the stock air filter box back in with a K & N drop in filter. Reset the PCM, and right back to pinging as soon as the computer set its fuel trims.

Put a paper filter back in it, and now 500 miles without knock or ping.

Oh well. I tried.

This does make me nervous as all hell to put the blower kit on it, though. I... don't think I'm going to now.

 

[Snoranger]

Preface: I hate you all, except @alwaysFlOoReD and @adsm08. You two are cool.




So, turns out the MAF on my 2011 is crazy sensitive to literally anything, even air filter varieties.

After finding out that the AFE cone filter intake I picked up on fleabay was the wrong MAF housing size, I went to the junkyard and picked up another air box cover to hack into a homebrew cone air filter tube:

View attachment 66982

Stock MAF housing with an AFE filter and velocity stack. Thought it would work fine.

Nope. Ping and knock city.

So, I put the stock air filter box back in with a K & N drop in filter. Reset the PCM, and right back to pinging as soon as the computer set its fuel trims.

Put a paper filter back in it, and now 500 miles without knock or ping.

Oh well. I tried.

This does make me nervous as all hell to put the blower kit on it, though. I... don't think I'm going to now.

So you tried to modify something and it didn’t work out... I’ll wait for something better to make fun of you about.

 

[PetroleumJunkie412]

So you tried to modify something and it didn’t work out... I’ll wait for something better to make fun of you about.

It really surprised me that the stoopid filter was the cause. Makes absolutely no sense to me.

I dont see how something as simple as the K & N drop in would cause so much headache. But, it does.

 

[RonD]

So we are assuming the Air Weight the MAF sensor was reporting was lower than actual air weight, so Lean mix until Closed loop and O2 feedback
But you should have gotten Lean Codes on both banks within a minute or 2 of Closed Loop

MAF only samples 10-15% of the incoming air weight so small difference changes to an upto 10 times difference at the PCM

The ACT/IAT air temp sensor is in with the MAF sensor on a 2011, but it shouldn't effect mix enough to get that lean

You are right it doesn't make sense for an air filter to cause that

 

[PetroleumJunkie412]

So we are assuming the Air Weight the MAF sensor was reporting was lower than actual air weight, so Lean mix until Closed loop and O2 feedback
But you should have gotten Lean Codes on both banks within a minute or 2 of Closed Loop

MAF only samples 10-15% of the incoming air weight so small difference changes to an upto 10 times difference at the PCM

The ACT/IAT air temp sensor is in with the MAF sensor on a 2011, but it shouldn't effect mix enough to get that lean

You are right it doesn't make sense for an air filter to cause that

I'm wondering if I still have an issue somewhere, and the air filter change is just masking it.

I really, really miss my 2.9...

 

[Snoranger]

I'm wondering if I still have an issue somewhere, and the air filter change is just masking it.

I really, really miss my 2.9...

Pull 2 spark plug wires and drill a hole in your radiator... you can pretend it’s a 2.9l

 

[09fx4guy]

That is really nothing to make fun of.

Its odd you had that problem. I had a K&N drop in for about 2 years without any issues. Then I switched to a K&N intake kit, and at least 8 years, no issues.

 

[Roert42]

Yeah, I am of the opinion you have something else going on and the filter just brought it to the surface.

 

[sgtsandman]

Boy, you have a knack for picking vehicles there buddy...

 

[PetroleumJunkie412]

Yeah, I am of the opinion you have something else going on and the filter just brought it to the surface.

I did.

Slowly dying catalytic converter that finally died.