I have been battling my 90 si with a b16a swap for a month now. I just redid the wiring relating to the oxygen sensors using a rywire harness. The car still has a partial throttle hesitation problem which I believe is linked to the rich running condition.

I only have 10 days in order to fix the problem, so I need to get this figured out fast. What should my next step be in diagnosing this problem? Should I go ahead and replace the o2 sensors, or is there something else I should look at first?

 

How high over were you exactly?

When I was about 15% over the limit with the Co's I simply changed my air filter, oil, added fuel injector cleaner and 94 octane

I also added about 1/2 liter of 99% rubbing alcohol and she passed no problem at all

Need more info though, how bad your failing by and on the idle test or the rolling

Knowing your setup/timing/recent changes would save some time

 

My CO was over twice the allowable limit. This was on a rolling dyno.

The car is still getting 25+ mpg, so the car can't be running THAT rich. The car seems to be fine from a tune perspective...although I haven't had an opportunity to verify the timing. I run 91 octane in it (premium here in denver.)

Any suggestions would be appreciated.