One of the things you have to put up with when owning a Subi is fuel surge on r/h corners if you are running a std fuel pump with less than half a tank, a Walbro will help a lot but not completely get rid of the problem.

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Beaten up old 98 Gen 2 Liberty, 13.0, stock V3 STI running gear.
07 Transit motor home
69 VF & 70 VG Valiants needing full restoration
Yamaha Zooma 50cc rocket hopefully going with the Transit.

OK guys, finally sorted.

Not AFM (I tried 3 different ones in the process), took it to RMS in the end as I had no idea.

Ended up being the O2 sensor! argh.

I didn't consider this as I thought the O2 sensor isn't used on wide open throttle and the ECU just falls back to it's maps and the AFM readings. He said it was running really rich (hence the bogging down) so even with the foot down it probably still had all that fuel to burn off first (I tended not to keep the foot down anyways once it started hesitating so I didn't blow the engine, haha).

Hey I dropped my car at RMS yesterday for similar problems with richness. Guessing that was your green gc8 then, see a red one there? Hope its just the o2 sensor.

What is the easiest way to test the O2 sensor? My car is not giving me any error codes but it hesitates slightly when partial throttle applied on low revs.

Adi

Yeah probably mine although I think there was another green one when I came in too. Your's the red 99/00 with black lip/side skirts, sti clear/red rear lights, roll cage etc.? If so, I spent a couple minutes just looking at your car, looked awesome.

Best way would be to swap with a mates one but failing that I'm not sure. I figure if you disconnected it all together it'd just go into limp mode and not give much help in figuring it out...?

Yea that was the one. Cheers! I recently repainted the lip with gloss black a few months ago and only used a $4 can from repco with no prep and it came out perfect and has stayed that way since. Also going to get the inside re carpeted around the rollcage and get a sound system custom installed in a way where it can be removed from track days to reduce weight and stop it get shaken around.

Nice one. You got the urethane or fibreglass front lip? Mine's looking pretty dull, might do the same.