Tracker emissions - Help!

My 91' Tracker failed emissions badly today...

As I'm selling it, I've gotta make it pass.

Basically failed on all 3 specs - NOx, CO, and HC...

My first thought is either the o2 sensor, or the cat...since there's
really little else (from my perspective, anyhow) to go wrong on these
engines, emissions wise.

I did change the plugs before the test, changed the oil and air
filter, and checked everything over..but still, a miserable failure.

Anyone have any related experience with Tracker / Sidekicks and
emissions problems?

What's the most common problem emissions wise for a 3-point failure
like this?

I'm most apt to try with just an o2 sensor to begin with, and go from
there...as I do suspect its overdue for one...but no SES light at this
point, though.

Cat may also be suspect...

Any suggestions / help appreciated. I suspect changing the o2 and cat
together will result in a pass, which is all I need to get rid of the
truck, but any other insight appreciated regardless..

Reply here, or email me pepper99@**NO*SPAM**.primus.ca

(Remove the obvious spamtrap before replying via email)

Thanks...Mark.

What's the mileage? If it's high, a new O2 sensor is probably a good call in
any case. The converter is more iffy however, it may or may not be bad.

--
Robert Hancock Saskatoon, SK, Canada
To email, remove "nospam" from [email protected]
Home Page: http://www.roberthancock.com/


"Mark" <[email protected]> wrote in message
news:[email protected]...
> My 91' Tracker failed emissions badly today...
>
> As I'm selling it, I've gotta make it pass.
>
> Basically failed on all 3 specs - NOx, CO, and HC...
>
> My first thought is either the o2 sensor, or the cat...since there's
> really little else (from my perspective, anyhow) to go wrong on these
> engines, emissions wise.
>
> I did change the plugs before the test, changed the oil and air
> filter, and checked everything over..but still, a miserable failure.
>
> Anyone have any related experience with Tracker / Sidekicks and
> emissions problems?
>
> What's the most common problem emissions wise for a 3-point failure
> like this?
>
> I'm most apt to try with just an o2 sensor to begin with, and go from
> there...as I do suspect its overdue for one...but no SES light at this
> point, though.
>
> Cat may also be suspect...
>
> Any suggestions / help appreciated. I suspect changing the o2 and cat
> together will result in a pass, which is all I need to get rid of the
> truck, but any other insight appreciated regardless..
>
> Reply here, or email me pepper99@**NO*SPAM**.primus.ca
>
> (Remove the obvious spamtrap before replying via email)
>
> Thanks...Mark.

try carb rebuild and adjust timing

Robrt White