Do I need new o2's again???
 

I researched and took the advice of people on here and bought Denso SG277 O2's instead of the typical bosch replacement o2's for long tube headers. Everyone claimed how much better they are and give more accurate reading. Well i bought them in august of last year, installed them in november some time (took me a while to get around to installing new headers). Since it is winter time i have driven the car maybe 100 miles on 2-3 different occasions since installing them. I am already getting codes because it says the switching points are two low.

Do i need to replace these sensors already? they are basically brand new but now has thrown codes twice after resetting them. Are denso's really better than bosch?

What should i replace them with as i don't want to use o2 extensions.

BTW, does Denso have a warranty as they had to be bad from the start.

98 VETTE REAR 02`s
 

We use stock 98 corvette rear 02`s, no codes works great.

I agree, do you have warranty? Otherwise,do you see bad O2 sensor symptoms?

What are bad o2 symptoms? I have really only drove the car twice and i didn't get to log them cause they were pretty short trips, and this last time out i'm pretty sure i took out the rear end. Each time i get codes on both banks first o2 sensors, as the second o2's have been turned off.

I have looked around and i don't see where denso has any sort of warranty.

is that your rear o2's i keep throwing codes p030 low threshold bank 2 is that rear and is it stating my cats are not getting hot enough? is that why the codes ? thats the same as you gpr? i think i'm in the same fix with high flow cats.

No, i am talking about the front o2's. they simply aren't working. I need to log it to see if they are actually switching, but the rear broke so won't be doing that for a while. I think i'm gonna stick with Bosch from now on. I have always used them in the past and these are the first Denso's i have tried and I'm not impressed.

thank you sir i was wondering which ones you were talking about . i'm still throwing p0403 codes. had one today as a matter of fact.

I bought a used pair and they worked for longer than the Denso's that I tried. The Denso's threw codes in short order; it just took the Corvette rears a little longer.

It's strictly hit or miss with O2's and LT's - mostly miss. No one brand is a solution for everybody. Denso's are no better than Bosch and vice versa. After verifying my AFR with a wideband I finally just tuned out those codes and forgot about them.