Hey folks,
I recently had my car tuned to 337awhp and 325 ft/lb tq. 25psi. It's been running great, but lately I got a CEL flash. However, this flash happened once, not repetitively, and occurs at the most random of ranges. Obviously all under WOT, but tests showed that it would occur at different times.

Example:
First run
WOT 2nd: CEL Flash once - 3.4k RPM
WOT 3rd: CEL Flash once - 4.4k RPM

Second Run:
0 Flashes through 2nd, 3rd, nor 4th.

Also to note, this happened after I fueled at a Shell Station at the beach. Gas perhaps? It's what I'm leaning (ha) towards. Anyway, just wanted another opinion of why this knock shows no consistency through the range. Thanks!

 

Tephra map has knock indication via CEL flash. This can be set to various levels of knock, you won't know what level yours is set at unless you check your map (or ask the tuner).

There are various sorts of phantom knock which occur during off throttle events.
However, the on throttle or WOT are the events you should be concerned with.

At this point, unless you know what knock level yours is set to, the severity of this is uncertain.
Many tuners aim for 0 count, 0-2 seem to have no problems (my Buschur tune had 2 at times), I believe when I checked my stock tune I had 5-7 counts LOL....
The truth is no one knows how Mits actually tuned the knock count, but running 0 is the safest bet....

Hope that helps.

 

I have already spoken to the tuner about the thresholds, so that's not much of a factor. My real question is just the lack consistency of the knock sensor. I just would think it would be more predictable, and not all over the place in different locations. Like I posted in my earlier example.

The AFR reads that it's not even close to leaning out, and yet I get these random events that can't be replicated.

Thoughts?

 

do a WOT in 3rd at 2000 rpm-5k, see if you get the knock light again.
i bet you can replicate the flash if you do it this way.

 

Went out and did it three times. No light.
I mean, it's good I guess, but it has me scratching my head.

 

it may not be the same every single time, unless you had an actual problem....
.. and its not necessarily dependent on A/F ratio.

What's the count set as? low counts can occur randomly or intermittent

 

High was set to 7 to 8. Low was I think 3 to 4.

Maybe I just don't understand the slow flash. Like I said, it was just a blip of the CEL. Is that what the slow flash is?

 

Rough roads can also trigger the light