Need Some Help At A Loss As To Whats Wrong

[t3intercooled]

Here it is. I have a fresh motor in my GN. ported and polished stock heads, gt3361e turbo, 214/214 cam bored .030 over and all the basics; alky, THDP, etc. Now here is the thing. I have a max effort 16 position chip with mass air and 42.5lb per hour injectors. It was driving perfect for about a week or so and started acting up a couple nights ago. The reason I think something is wrong is that on my scanmaster at idle in the O2 milivolts spot it reads in the 800s which is good, when my chip hits cruis mode it goes to the high 30s which is good too, but the thing that weirds me out is that when i press on the gas the readings go between 40-70, which it never has, and i think that that is bad. Now every now and then when i am letting off the gas on the freeway per say the readings intermittently change drastically, they go from 100 to 80-0 down to 400 back to 800 down to 100 and so on. Sometimes it stalls and sometimes its insanely hard to start. Any suggestions what is going on? Is it possible I could have a bad O2 sensor? Cause it didn't do it after i put the motor in. I was running good for about a week and just started acting up a couple weeks ago. When I give it boost even though its between the 50s and 70s I still get no knock which is good, and thats with the alky turned off. Any help is greatly appreciated. Thanks.

 

[BlackBandit]

The only time your o2's should remain steady is during deceleration or WOT. The rest of the time the computer is adjusting fuel to according to the o2 which is a narrow band sensor. This means it only reads rich or lean. (in a nutshell) The ECM is constantly adjusting for one of these conditions based on info from the o2 so it's pretty much pulling fuel until it goes lean and then adding fuel until it's rich. This is why the o2 voltage jumps around. Now, if it's happening at WOT then that's a problem. HTH. james.