2005 WRX hesitation/flat spot

[dolomite16v555]

Hi all,

My 2005 WRX has an intermittent spot of hesitation when accelerating in 4th & 5th gear whether on part or full throttle, it boosts very well in 1st, 2nd & 3rd. The car has a stage 1 remap done by Andy Forrest (by a previous owner) and associated intake and exhaust mods to suit the map. I fitted an up-rated Walbro fuel pump thinking that would cure the issue but it hasn't.

Any advice appreciated.

[dolomite16v555]

Thanks for the info, think I need to rule out the MAF first and take it from there.

[dolomite16v555]

Cheers - will give that a go, would the ecu reset upset the remap? Would you go for standard replacement plugs or something like NGK Iridium in a cooler heat range?

[dolomite16v555]

Cheers, got the plugs so will fit them this weekend and see if the problem goes away.