Had most of the items in my signature put in last week (except the 680s and the MBC), the car was running great! Then while cruising at 45 in 5th I couldn't accelerate. Every time I try to use more than about 10% throttle in any gear it bucks and even backfires. Took it back to the shop and everything looks connected, even did a boost check and tight as a drum. It did throw a code which they said was the rear O2 sensor. Reset the code and even pulled the negative terminal and nothing changed. It revs fine and even goes boost if not in gear, but the minute you start moving and use over 10% throttle same symptoms again. I drove it all day before this happened went boost several times, cruised at 75 for a while. Car felt fantastic. Got a boost gauge now and it is not showing anything unusual for vacumn, of couse can't get to boost except when out of gear. By-the-way the alchohol kit was put in a tested, but setting are so high that it is basically disabled until Al tunes the car in Dallas and yes the check valve is working fine as per the boost check.
If you have some good advise, I'll really appreciate it. This is my daily driver and I'm herding a PT cruiser from Enterprise in the meantime. Please save me!
Thanks,

 

Bump

 

that happened to me where i couldnt accelerate, and i had to throw it into fifth and floor it down local roads just so i wouldnt stall, and even then it was only going about 20 mph. the reason the body shop told me was because they put some hoses on backwards after they worked on it. they said the intercooler hoses but idk they had no idea wut they were talking about. once they fixed that the car ran fine

 

OK. Finally got it! The fuel pump partialy failed (New Walbro 255), would not go past 43lbs pressure no matter what. Changed back to stock and everything in back to normal! Waiting for replacement pump now as the 680s sure won't run on a stock pump.