Weird Scanmaster numbers....

[Cakes]

Today I was driving around and I wanted to get some a reading from scanmaster of my 02s and knock. It was a short blast from around 10-55 mph (1st and 2nd gear) and it stuttered bad and then took off really hard around 40 mph or so and then I checked my numbers and it said 072 and 0.0 for knock. I know this means I am running dangerously lean but what can I take from this reading? Is it a false reading due to short WOT blast? This doesnt happen all the time Usually it is around 810-840 and I know this is rich and it has no knock. Any advice would be greatly appreciated. Thanks!

 

[mxmstrmel]

Sometimes it happens to me too. O2s usually stay around 790-810, but will sometimes read 300+ or 200+. I think once it dropped below 100. I was told not to take the O2 readings for more than they are. I just pay more attention to detonation.

 

[gnXfan]

Originally posted by mxmstrmel
Sometimes it happens to me too. O2s usually stay around 790-810, but will sometimes read 300+ or 200+. I think once it dropped below 100. I was told not to take the O2 readings for more than they are. I just pay more attention to detonation.

I agree - look for the knock. Are your ccs ok?

 

[Turbojorge]

The same thing happened to me over the weekend and it resulted in changing the 02 sensor. The one that was one their took a dump after only 1 gallon of c-16 went threw it. This time, I got no codes from the SM and the cross counts were normal. I new it was gone after I recorded a .695 at WOT with 17 psi and no knock. It was not a heat one. I got a new heated one yesterday and now every thing is back to normal.

The way I can tell for sure that it's the 02 sensor is because my car stutters and will eventually backfire out the intake if I stay on it.

If you run lots of race gas, you'll be better of with a heated 02 sensor. (AC Delco part # AFS 74)

Later