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Discussion Starter #1
Ever since I changed the downpipe the car has ran lean... I've added fuel..... ALOT more than it should have been (almost 30%)

No matter where I set my lamda while in steady state driving the AFR runs from 16-18:1(in closed loop) and for a long time it wanted to idle at the same AFR.

I finally got the idle fixed... and most of the steady state driving issues straightened out by lowering my TP_for_WOT settings low enough that it should run off of the base fuel table in open loop... well the dumb thing keeps going to CLOSED LOOP even with my TPS_for_WOT set so low that it should NEVER go to Closed Loop.

Here's the kicker... when I set the TPS that low it stays in OPEN LOOP about 90% of the time.... BUT I'm still seeing 16-18:1 AFR while steady state driving AND when I go WOT IT WILL NOT FATTEN UP MY AFR it doesnt even change from 16+ AFR and yes its in OPEN LOOP when I checked it.

Changeing pipe diameter should not cause this many problems. When I put the new bungs in they are within an inch or so of the old ones so they should not have effected it much and I did install a new front O2.

I have a pretty good grasp on what I'm doing and I know this shouldn't have been no more than a small adjustment at best.

Any ideas??
 

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Discussion Starter #3
Well today I put in an older tune that worked perfectly prior to the 3" DP/Flex... started it up and it still ran odd (lean w/weird idle). So I put it up in the air, welded up a couple of small leaks... so small you cant even hear them, started it back up... same old crap.

So the only thing I changed was an O2 sensor (put in a brand new one)... and it just so happens I had an OEM sensor just laying in the garage... swapped them out, started it up and it ran ALOT better... so I added 5% fuel to the tune (down from the 30% I had to do earlier).. and it actually runs good the AFR is really close to what I like to see, EGT's are normal, WOT goes fat just like it should.... needless to say I'm alot happier than I was Friday.
 

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good to hear you gotten everything situated...when are you going to get it dyno tuned again to see what kind of gain you might've received from upgrading 2.25" to 3.0"?
 

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Discussion Starter #5
eventually.... when its warmer out and I can retune it for warmer weather.

In winter the air is soooo much cooler... but its ALOT dryer... hence more chance for deto.
In the summer the humidity is higher and you can run alittle more timing... and timing is power.
 
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