afr spikes

What is your question?

Hi, I have a 2007 Chevy Colorado, with the 3.7l i5. I have performed a cat delete, installed a WB O2 sensor, and tuned out and removed the second NB O2 sensor. This was all performed years ago, and the WB install/NB delete came after the cat delete. That's important to the description because I couldn't tell you whether or not this issue occurred before the cat delete. What happens though, and it seems to occur more often lately, is that I will get AFR spikes at cruise. It will shoot up to between 16-17 for a minute or 2, then will drop down to 13-13.5. It never spikes a WOT, however, so I'm not too worried about engine damage. Can anyone tell me why this is occurring, and what I can do to resolve the issue? Thanks, and have a nice day

How long has your 2007 Chevrolet Colorado had this problem?

About 2-3 years

Visitor

in Columbus OH

Feb 23, 2020

1 Reply

Popular Answer

DaveJMon Feb 24, 2020

Hi, I hate to be a bit of a pest, but removing your catalytic converter is unlawful and damaging not only to the atmosphere but also to your vehicle's control systems ultimately. You'll get no proper operation of engine performance by removing key components. Sure, anything can be done, and a shop that specializes in these unlawful activities may be able to assist you. No one in this forum can or will be able to assist you in this concern -- for a few reasons -- including that you can't really overcome the variables created by removing factory components without some kind of customizable programming done to a processor.

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