Bad o2 sensor messing with the tune???

[evood69]

Little background first, I've got a Jeff.O chip on my 1g. I've had problems with it for quite sometime now. (THIS HAS NOTHING TO DO WITH BADMOUTHING JEFF.O OR HIS CHIPS)!!!!! Just want to make that clear, because he has been nothing but helpful. Anyways, my car threw a CEL about 2 weeks ago and it was for the front o2 sensor. Here's my main question can the o2 sensor being bad cause his chip to basically be pointless? I've had the problem for 3-4 months, but I was thinking maybe the o2 sensor was just getting worse and worse this whole time until it threw the CEL. I havent thrown the new o2 sensor in yet, but will Monday. Just trying to get information about this from people who know a TON more about this as me.

Thanks!

 

[RyanSaiki]

I believe the o2 sensor can screw up your tune. I have a 2g and we were just recently trying to tune it via DSMLink, and the front o2 sensor was pretty much dead which threw off all our readings. So all we could do was get a base cruising tune, but no WOT tunes until I get the sensor fixed.

 

[evood69]

Well I know it affects it to some extent, but I wasnt sure if it affected it enough to basically anything past 15psi I get CRAZY knock. I've always been able to run 15psi fine, which is what 2-3psi more than stock.

 

[RyanSaiki]

Well I know it affects it to some extent, but I wasnt sure if it affected it enough to basically anything past 15psi I get CRAZY knock. I've always been able to run 15psi fine, which is what 2-3psi more than stock.

Do you have a wideband to monitor your a/f ratios?
Have you noticed anything else different with your car? Maybe some other sensor went out. Sorry i'm not much help. I don't know too much about these cars.

 

[evood69]

Do you have a wideband to monitor your a/f ratios?
Have you noticed anything else different with your car? Maybe some other sensor went out. Sorry i'm not much help. I don't know too much about these cars.

No my wideband went out, however I log and can read my o2-r's which can give me a decent idea of my afr's. But I'd have to check on my logs to see. But no I havent noticed anything different.

 

[RyanSaiki]

No my wideband went out, however I log and can read my o2-r's which can give me a decent idea of my afr's. But I'd have to check on my logs to see. But no I havent noticed anything different.

If you can still log your A/F ratios then you should see something wrong with them whenever you hit KNOCK.

 

[bomper04]

If you have a faulty o2 sensor it is not unlikely that you could experience not just the CEL but you may also run into slight driveability issues. When o2 sensors start to detereorate sp? they can become biased toward the rich or lean side. There response time will be longer than that of a normal operating o2 sensor. So in response to your question, I believe that your o2 sensor may be slow responding or lean-biased and causing your knock issues that you are currently experiencing. Does this happen at WOT? Cruising with slight accel? Post your log and take a look at your o2 sensor switching pattern if available over a time axis of at least...5-10 seconds.