qwiketz

Hi guys. Would either of those items cause the o2 to read lean and therefore cause the engine to dump more fuel?

My o2's are running lean but my wideband says the car is running rich. I need to get under the car to determine where the wideband is postiioned in relation to the o2 sensors on my long tube header.

I'm fishing, but curious here.

LS6427

iTrader: (2)

yes and yes

hrcslam

Yes, but the wideband and the narrowband should both read lean or rich respectively. Have you calibrated your wideband?

If you do have loose O2's or an exhaust leak pre-O2 you need to get that fixed.

LS6427

iTrader: (2)

Even if the leak is after the 02 sensor it will still suck fresh BACKWARDS and the 02 sensor will read it......depending on how close it is to the sensor of course. I had a leak about 8 inches after one of my 02 sensors and it was affecting it. I had it spot welded and drove off running perfect.........

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hrcslam

Good point.

qwiketz

I replaced the trans not long ago. Maybe I need to tighten down the bolts on the collectors better...

dailydriver

OK, but just how far past the O2 sensor can the leak be and still effect the readings, send codes, etc.?? A foot, 2 feet, MORE???

My y-pipe to intermediate pipe junction is leaking, and I can't get it to seal with ANY clamp type (tried the stainless band clamps, Torca narrow clamps, etc.), and I still have stock factory iron manifolds, and OEM type Magnaflow downpipes/catcons, so the front 02s are WAAAYYY up there, FAR away from that y-pipe collector leak.
Is that STILL close enough to throw a code/cause problems?

qwiketz

well, another possibility off the list. My exhaust worked loose and my gaskets were shot. Once fixed, the car still isn't running right (possible vacuum leak) but oh well. It was a $10 fix and an hour on my back.

On a side note, my o2's and wideband was right next to the exhaust header collector

RatCityRex

iTrader: (3)

Alot of people forget that wideband read how much air is left in the exhaust, that being said.... If you have a rich misfire your wideband will read lean not rich.

2000Phoenix

iTrader: (2)

It’s lean. So you think plugs wires or coils?