PLX wideband kit.

Its really low, 12-12.4. (even high 11s sometimes)
On wot its mid 13s.

What could cause rich cruising afr? A wideband suppost to show idle, cruising and wot right?

 

widebands show your Air Fuel Ratio, independent to your engine's load, RPM, or anything. I'm assuming you're on stock ECU? Otherwise you could just take or add fuel wherever needed, but depending on your setup, boost levels, etc., you should see as close to 14.7:1 (stoich) on cruise, for economy, and under load it varies by setup and boost levels, but should be in the mid 12's (under stockish conditions).

What would cause rich cruise AFR's? A lot of things, but knowing your setup might help with suggestions.

 

It is normally a failed O2 sensor that will keep your car from going into closed loop during cruise and maintaining that 14.7:1 AFR.

First, if you had the PLX wideband O2 sensor in the stock location you would need a simulated narrow band signal back out of the PLX to tell the car's ECU when to go into closed loop.

Second, don't run a wideband O2 sensor in the stock location as it will shorten its life due to excessive heat.

If you are already running the wideband O2 sensor in a new bung farther back in the downpipe and have a working stock O2 sensor in place please disregard this post

 

Or you messed up the afm when you *played* with it.

 

he, he.

My stock o2 was disconected, but i didnt think it would have that much effect.

The bung is far back, 45"-50".


i recalibrated the afm with the dmm. its 2.5v at idle. and then i tightened it 1 tooth more, tomorrow see what afr will be.

The air bypass screw will have a nice effect on rich/lean tunning -10%/+10%, almost like a free afc. If anything just remember how many turns you make.

 

I have a heat sink on mine in the stock location, works great and it makes the lag not quite as bad




just plug the stock o2 sensor back in the original bung and you'll be good to go.

 

Thanx, it was the stock o2 sensor, now its 13.7 idle, mid 14s cruising.