Twsdid

Hey all did a search but nothing difinative popped up as far as an answer goes,, running 04 5.3 turb, mafless, 2bar map & just had full dyno tune a month ago 450whp at 8psi which is more than I need in a light bum c10, my tuner is now away on hol's so can't ask himmy ???? My issue truck runs mint pulls hard , round town running etc my AFR always between 10.5 under boost & 13.5 normal driving, but my issue on open road driving trying to maintain 100kph{speed limit here} she pops & misses AFR drops to 8.5/9 if I let my foot off AFR jumps straight back to 13ish & same if i load it a slight buit more AFR jumps straight back to 13ish but obvioulsy speed increases & the five oh will be on me .. I can maintain it being on & of the gas but its a pain ... Any ideas? tuning issue?or may be something mechanical air leak etc


cheers in advance

The BallSS

iTrader: (9)

10.5 is pretty rich, I'd like to see 11.5 ideally at WOT and closer to stoich at cruise 14.0-14.5.
Post the tune and a scan from when it acts up.

Full Power

I'd have a close look at the MAF sensor grommet, make sure you are getting good tight ACTUAL manifold pressure reading.
Get a cheap BLUE Driver scan tool, verify O2 sensors are switching, MAF and IAT and Coolant temp readings are in ball park.