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i have a autometer air/fuel ratio gauge in my car and i know most people say that they aren't accurate but anyway... i have noticed that when i am driving on the highway in 5th gear and floor it, the car will accelerate but then when it gets to about 4 or 4500rpm the gauge will go from 3 green bars ( rich ) to the last red led's on the other side ( lean ). i pulled out no.6 plug and it was alittle white not alot and i have had those plugs in there for about 3 months or so.

i have a walbro ( *spelling ) 500hp intank pump and a Apexi BOV.. most people with this kind of mods are running rich as hell.

also the car will backfire sometimes.

its a RB20DET 4WD so if anyone has any idea's that would be great..

other mods are 3" turbo back exhaust, pod with CAI and thats about it.

Thanks guys :P

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Impossible to say until you know whether you have a problem and what the problem is.

You should be more worried about the potential of running it too lean for too long and melting an important engine part, which will end up costing you a couple of grand to fix rather than a couple of hundred. If they try and sell you a new aftermarket ECU that's one thing, but if your fuel pump or an injector is on the way out then you should definitely replace it.

air/fuel gauges are accurate to the extent that they can show you an indication of "rich" vs "lean". that's only richer than stoichiometric though, just because it says rich doesn't mean your fuel ratio under load is correct because stoich is 14.7:1 and you really want to be running somewhere in the region of 12:1 under WOT... BUT, if you give it a bootful and it goes rich and then comes back to lean again then stop booting it, and get it checked ASAP. If the meter is reading correctly and it's running that lean under load then you have problems!

Best case the meter is wrong. Worst case something needs fixing, get it dyno'd and checked and then you'll know.

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