replacing the Pre-cats or not.... that is the question!

turbo_fox said:

I had the same problem on my 99. I datalogged with the PC and it was the same, upstream o2 matched the downstream. I just swapped the upstream and i have no light anymore. It wasnt too bad, took me about 45 minutes to change.

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Well, looks like i will be headin' to Autozone after work :laugh:. Looking at O2 sensors, I see that there are 2 plug types. there is a Square and a circular one. Which one I need (aka in-front of the cat? I assume that either side does not matter).

And i looked up the Boch sensor, apparently it was not OEM, but just OE!

for a 99 if you have the return fuel system it will be a square plug. if its a returnless its round also.

BrApple said:

for a 99 if you have the return fuel system it will be a square plug..

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Too the search function! (I have read a small amount about the return/returnless system, but decided i would not look into it untill i needed too... well I guess the time is calling :laugh:.

BrApple said:

if its a returnless its round also

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Also? as in all 4 of them would be round if that were the case?

yet again, thanks to all for all the input:laugh:

Edit: Nevermind about the "also" (post #5): http://www.contour.org/ceg-vb/showthread.php?t=43124&highlight=return+fuel+system Thank you BrApple:laugh: