BeerTurbo Posted September 17, 2023 Share Posted September 17, 2023 howdy trying to diagnose issue with my fuel consumption. and some other gremlins. when datalogging i cant find a short term fuel trim, i recall using this in the past on forscan, is it redundant or called something else in the logger? when data login the long term fuel trim, say its at 0.9. is that adding 10 percent fuel overall for the closed loop fueling tables? i tonight replaced my 02 sensor as when watching the live data from the old o2 sensor it seemed to just peg 0.3v for a bi then peg 0.7v for a bit then swap around. i havent actually lodged the new sensor. but ill see how the car drives tomorrow. cheers Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted September 18, 2023 Share Posted September 18, 2023 Have you loaded the default layout file? They are in there Quote Link to comment Share on other sites More sharing options...
BeerTurbo Posted September 18, 2023 Author Share Posted September 18, 2023 11 hours ago, Roland@pcmtec said: Have you loaded the default layout file? They are in there Cheers roland. Turns out i was just to tired to use a computer. It was already in my active logging parameters. For fun follow up a new o2 did fix my issue. The 02 trace now just wiggles around the curve constantly. Previous o2 would either be 0.8 or 0.3 from memory. Reason i pulled it up was a couple times on cruse control with the van it started running so lean it would misfire for a second, of cause it would stop pretty quickly and i was left scratching my head, thinking the fuel filter was clogged from the nullabor fuel stations. I noticed in city hot idle on my afr gaige it would just start working its way lean and around 1.1 to 1.12 lambada it would misfire at idle. So then dataloged n noticed the o2 doing strange things and the fuel trims working overtime 1 Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted September 19, 2023 Share Posted September 19, 2023 If you've got a big dump pipe make sure the O2 is not located too far away from the turbo. Otherwise you'll need the play with the transport delay. The wiggling is expected and normal. It should constantly oscillate rich lean at a fixed frequency. This is to ensure the catalytic converter works correctly and passes emissions. Quote Link to comment Share on other sites More sharing options...
BeerTurbo Posted September 19, 2023 Author Share Posted September 19, 2023 8 minutes ago, Roland@pcmtec said: If you've got a big dump pipe make sure the O2 is not located too far away from the turbo. Otherwise you'll need the play with the transport delay. The wiggling is expected and normal. It should constantly oscillate rich lean at a fixed frequency. This is to ensure the catalytic converter works correctly and passes emissions. Yeah normal widfling with new one. Old one would just sit at one spot for 10 seconds sometimes a minute Ill look at delay it is a 4incher dump probably a tad further away than a stock location. Its xforce dump. Ive not played with that before. Is it expected to increase or decrease time? Quote Link to comment Share on other sites More sharing options...
Roland@pcmtec Posted September 19, 2023 Share Posted September 19, 2023 Increase time. If the O2 is oscillating at the correct frequency with no DTCs though you can simply leave it alone. The correct frequency I believe is in the workshop manual, you could also google the patents or find some stock datalogs to see what it should be. 1 Quote Link to comment Share on other sites More sharing options...
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