Hi all, new here and came across this site hoping to find some help... I have recently got an 88 tbird 5.0. She was sitting in a friends field for about 4 years, but she runs fine, but cannot pass the idle part of emissions. any ideas, please?

How does Utah test emissions? Exhaust gas analyzer or a plug in to the computer?

Since its running fine I assume you are getting just a slightly rich exhaust at idle, correct? Problem could be cause by several things. Sticky injector(s), O2 sensor(s)...

John Draxler at the Thunderbird Ranch is pretty familiar with this vintage Thunderbird as well as the older cars. Also, your car is new enough that its covered by the AllData database used by most shops. Difference is you can buy a subscription for one car at a pretty reasonable price.

Good luck

Utah runs emissions by exhaust gas analyzer. And you are correct, it is running rich at idle. I will try to seafoam the engine. if not that, then I'll get new o2 sensors. thx for the info!

My mechanic swears by the injector cleaner made by GM, in theory, for GM cars. However, works on all brands and according him works much better than anything else. You may have to go to a GM dealer to get it, some bigger Delco parts stores have started to stock this. Try that if the seafoam doesn't work. It is about $25 a bottle.

ok, so I took it in to get tested again, it failed. Always in the same area, failing the hydrocarbons passing is 220ppm mine is (at this latest test) 533. I may have to get new catalytic converters.

Sorry if I'm telling you stuff you already know but a shop with decent equipment should be able to tell you if the cats are bad. If the cats were bad you should notice this particularly at highway speeds and when you try sudden acceleration at speed like hitting passing gear. Did you already find out that O2 sensors are good?

hey no worries about telling me stuff
When I accelerate on the freeway, there's no lag, but there is a rattle. But I believe the rattle is a lose heat shield. I still don't know about the O2 sensors yet. the mechanics haven't looked at it yet. Btw, would you happen to know what it's supposed to idle at? when I had it tested, it was idling at around 728.