422Mouse

I assume this is multiple misfires, no DTCs or pending DTCs are set, yet it flashes periodically after a few minutes of normal driving.

Anybody have any ideas?

TIA

Drew

<small>[ May 04, 2002, 08:06 PM: Message edited by: 422Mouse ]</small>

XLR8NSS

iTrader: (4)

If you are using Atap to check the codes try looking at the "Freeze Frame Data". It will show a list of codes for your car. When you select one it will show all the info about the car when the code was set.

Sometimes Atap doesn't show any codes under the "Diagnostic Trouble Codes" section even when the car has a SES light. <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

If you get tired of the SES light just take the bulb out. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

John <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

422Mouse

It never turns on the SES light to store a code, it only flashes periodically.

And yes I'm using the DOS version of Autotap to check it.

Drew

Pro Stock John

iTrader: (34)

Drew, Paulie on here has had that problem, I think it's MAF related on his car, like one of the wires is bad.

422Mouse

Now that makes sense, the only pending DTC it had set was a "MAF low FREQ" code. I took out the MAF and checked for any loose connections or visible damage, there was none, so I put it back together to see if the problem was fixed.

Now I still get the flashing SES with no DTCs, pending or otherwise.

The shop that installed the engine also descreened the SLP MAF and thats probably when the damage occurred.

I'll put back in my stock MAF and see if it goes away.

Thanks PSJ

Drew

<small>[ May 06, 2002, 06:20 PM: Message edited by: 422Mouse ]</small>

Pro Stock John

iTrader: (34)

beep@attglobal.net is Paul's email address.

He hasn't fixed his yet, but I know his car keeps blowing an accessory fuse and the MAF was the culprit. We thought broken spring at first but it sets no codes...

I follow no 1

iTrader: (6)

My bros car set a flashing code(Which said something about a maf freq.) at him and it was a broken 941 on the exhaust side.But when another one broke later it didn't even throw a code and he had 2 spings bad. Mine flased at me the other night and I got scaredI had just changed plugs and hadn't reset my maft.No problem sense and I didn't find anything on the pc with atap or tech 2000.

Reboot

iTrader: (5)

I used to have the same problem even though I had P0300 misfire code deleted but not misfire detection. Once I had misfire detection disabled the light stopped flashing.

Use ATAP to check your misfires by cylinder to verify they're ramdom, then have misfire detection turned off.

422Mouse

Reboot:

Thanks for the great info. Any drawbacks/problems with removing misfire detection that you know of ?

I swapped in the stock MAF last night, so we'll see if the flashing SES goes away.

If it doesn't, then you're probably correct and I'll have Superchips take out Misfire detection.
I have to send the PowerLoader back to them to fix a cold start problem anyway.

Drew

Reboot

iTrader: (5)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 422Mouse:
<strong>Reboot:

Thanks for the great info. Any drawbacks/problems with removing misfire detection that you know of ?
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I haven't had any issues. I was able to cure two problems by having misfire detection disabled. No more flashing SES and my converter locks up again, everytime.

It's very important that you log the misfires on all cyliders to make sure they're random before disabling it.

If the problem is related to misfires I doubt the MAF will help.

422Mouse

Actually, I changed out the MAF because the one pending DTC was a "MAF low Frequency" (don't remember the number) code.

So I assumed it was the descreened SLP MAF that was causing the problem.

I'll take your advice and AutoTap the misfires for all cylinders to see if they're random.

Drew

<small>[ May 07, 2002, 09:52 PM: Message edited by: 422Mouse ]</small>

422Mouse

Update:

After swapping in my stock MAF, the problem still exists. Happened today while I was driving into work. So the problem wasn't the SLP MAF.

The stock MAF did get rid of the audible pinging the motor had developed since the SLP MAF had been descreened though. Looks like it doesn't like the SLP without the screen, even the descreened SLP brought the A/F ratio right at 13.5 at WOT on the dyno. Thats were it made the most HP/TQ.

I'll autotap tomorrow to check for multiple random misfires on all cylinders and if they are present, I'll have Superchips remove Misfire detection.

Thanks again to Reboot

Drew