unstephenk

I am having trouble passing my State Emmissions Test. What do you recommend I do to pass the test?

I have also heard of people having problems with the oxygen sensor. Will replacing that part help at all?

I have a 1991 Lexus LS400

Zoraone

I would do a search regarding other people with the same problem.

Also, check here:

https://www.clublexus.com/forums/sho...d.php?t=377171

This seems to be doing a lot of good for many early 1UZ owners

unstephenk

Search was unsucessful. Someone help me out

Zoraone

I'd start with plugs, wires and a good top end cleaner (seafoam) as well as replacing the coolant temperature sensor.

If that doesn't work go to the o2's, cats and EGR system.

Do you have symptoms of bad fuel economy, lost power?

python

iTrader: (4)

first of all u have left out way too many details for anyone to answer this question.....is ur check engine light on? why did it fail?

unstephenk

Check engine light is not on. The only thing I can't pass is the emissions test

Lexmex

What are your emissions readings (i.e., HC, NOX, CO)?