P0088 and the latest firmware (flash)...
 

I got the dreaded Poo-88 a bit over a week ago, actually two incidents, both unloaded and after a good 45min of steady state 70-75mph on the nice level highways here. Both times it dropped out of cruise control and was then stumbling and lacking power.

I stopped by my dealer last Friday and they were able to have a tech do the PCM flash update while I waited (no charge either), so hopefully the expanded tolerance on the pressure will take care of it. If not it's still under ESP, but I'd be happy if that was the end of it.

At any rate, I haven't seen the P0088 again so far, but I noticed after the firmware update that the overall performance and responsiveness seemed to have improved. Now that it's been a week of various trips I'm convinced there actually is a performance improvement.

The last firmware I got was I believe 11B25, the slight update that came out shortly after 11B23. Since then the truck has run fine, but since this latest firmware it seems to have improved throttle response and hits higher peak HP (as reported by my Scangauge II) when accelerating from my street out onto the main road which is a 65mph zone.

If you haven't had a firmware update in a while you might want to see about one.
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All I can say is some of us still threw the code later on.

So drive it the same routes and find out. Mine threw the code again while in Texas so I had to have it replaced.

I would clear it and within a few miles it was coming back so that mean't it was needing replaced.

I tend to think higher engine loads over longer distances will bring it back sooner if it is truly out of wack.

There wasn't any particular load when I got the P0088, just 75mph on level highway, unloaded, perhaps 50hp indicated on the SG II. Who knows if it will return, if it does ESP should cover it.

My point was that there seems to be a performance improvment in the newer firmware so if you haven't had an update recently you might want to get one just for that.

There's been 2 updates since the 11B23. They don't document what were the changes.

The calibration version suffix for my truck ended in -HCA when I got the 11B23 early on. -HCB must have been the one where they changed some stuff to deal with P0088 codes. It's now version -HCC.

I never noticed any performance changes (but I wasn't monitoring anything) however, regens seem to behave differently on the latest. I used to see DPF temperatures shooting up to 1250-1300F during regens. Now with the -HCC version, it seems to top out around 1150~1200 more often than not. Not sure if that's because my DPF is filling up with ash or what, or they lowered the max DPF burn temperature for some reason.

I'm going to drop my DPF and blow out some ash again one of these days when I get bored and see if there's any difference

My theory is that they detuned things a bit with 11B23 when they were having a lot of warranty issue, and since that time they have figured out the problem and restored the original tuning.

Really here in 2013, nearly 2014 they should dump the secrecy and having to go to the dealer for a PCM flash. Just put the damned firmware on the web along with release notes, a USB port on the PCM and let folks just download it to a flash drive, plug in and update much like the nav system or any number of other user updated items.