AFR running extra rich at WOT?

[ZPIracing]

Originally Posted by largeorangefont

A narrow band AFR guage is useless. Get a wideband for a more accurate picture of what is going on.

Higher octane will not change your AFR. the car will run 14.7:1 in closed loop while putting around, but in WOT situations the car needs more fuel to keep EGTs down. This is a scenario where it is not practical to run the theoretical limit because you will harm the engine. This is typical in ALL cars, and more pronounced in FI applications.

Your intake could very well be contributing to this issue. While I wouldn't call just below 12:1 too rich, but it could probably be leaned out a bit safely. Generally intakes make power by leaning the car out a bit, but yours has a tight 180 degree turn right before the MAF that could be throwing things off a bit.

Ashley

This is very true. The stock ECU should have you running somewhere in the 12.5 range at WOT and 14.7 at part throttle. This is what we typically see out of toyota ECUS. The Rich reading on a narrow band ecu is about as useful as that one buddy who always wants to help but breaks the parts he attempts to install.

I would put the thing on a dyno with a sniffer and get a better idea. I am not sure that I would be that worried about it if all you have modded is an intake. I am confident the car is safe.