Hi,

I’m modifying and moving this content from the Sticky I previously had posted in, to try to get some feedback. Moderators, if this is a problem, feel free to delete.

I just returned to Illinois from Quartzsite towing my 12,000# fiver. I have 123k miles on the '09 LMM at this point. I had no problems going down in January, but several P0087 episodes on my return last week – big hills, a couple hours into the day, lower fuel level in the tank (the usual culprits, evidently).

This is an absolutely stock truck, with auxiliary filtration, regular Power Service throughout its life, regular filter changes, and regular Chevy dealer service at the same competent location. No lift pump (duly noted, John).

Obviously, working through the P0087 Sticky thread gives possible short and long term answers. But my solution for getting home the last 1,000 miles -- starting in western Oklahoma -- was to keep post turbo EGT's in the 1,000 degree range, and never more than 1,100. I used that as a proxy for the temps the injectors and incoming fuel were experiencing. I did this by doing a lot of manual gear selection on hills. (I recall only one post in that entire Sticky thread that mentions that approach.)

My dealer has just had it for two days, and as I expected, found nothing wrong. The injectors tested solid (as they did just before I left actually). No codes were remaining, of course. And absent the load from towing a heavy trailer on hills for hours while hot, there was no way to get their equipment to register my issue. In addition, at my request they inspected all fuel lines (solid or already replaced), the fuel cooler (clean), and they found no leaks anywhere.

These are two guys who know the truck since new, have serviced it thoroughly and regularly, and otherwise have my confidence. They did offer a thought that freeing up the exhaust might help keep overall temps down and thus keep the returned fuel cooler. Coming from a dealership, I found that interesting.

But for now I'm guess I'm going to drive on carefully, and see what the future holds.

Any thoughts on the exhaust change idea from anyone? How about my strategy of using EGT as a proxy for fueling performance? Or for that matter, on any other recent developments on this P0087 code problem for medium age trucks that work hard?

Thanks for your ideas.