Little help with poor performance!

I race my 96 Riv on weekends at a local dirt circle track and have been having a problem with hesitation especially in the ealy part of the show when the car hasn't ran as much. After running for the first part of the show the car really comes alive like it has "warmed up enough" and is ready to race! I can't figure out why but am leaning toward one thing that is left that I haven't taken a look at yet. When I removed the exhaust off the car completely I left the O2 sensor in place but not actually in the line of the exhaust. Imagine the cat removed but the O2 sensor left in place. Do you think that the O2 sensor needs to be closer to the heat of the engine and will that cause the hesitation I've described? Is there a way to bypass the O2 without major consequences? Please help me get back to the winners circle... 5 Wins and wanting more!

Thanks!
Walt

I'd think the #1 O2 should be in the exhaust stream. #2 (near cat converter) doesn't matter. How many miles are on the engine? If you had a scan tool, it would be easier to verify what's working and what's not. Just an idea. If you have a laptop computer, it's a valuable tool that can be used for multiple vehicles.

I just want to make sure that I read this right, you race your Riv on a dirt track? Have any pictures of you racing it. I bet you get some weird looks at first.

Here's a link to a page I made of some of the pics that i have.. I don't have the most current winning pics added. There is a total of 5 wins to this date!



Enjoy

https://rivperformance.editboard.com/racing-kill-stories-f10/007-racing-home-page-t2848.htm#32353

I must have missed that thread. Pretty cool. How does she handle in the dirt?

As for your problem, I am not really sure. Have you tried changing the top o2? It should be connected to the exhaust around the rear exhaust manifold. The rear o2 sensor will tell the computer if the cat is working or not.

Given that you are racing on a dirt track, my first guess would be to clean your MAF sensor.