Pontiac Owners Club UK

Hi
My mot is due in a couple of months and I need to get my emissions down before taking it in.
I suspect there may be a problem with the cat but I don't really want to buy a new one as I want to remove it.
last mot the emission was 6 percent.
It's a 91 3.1v6 firebird
Any tips on where to start would be great.

Mark

That seems high as my gas guzzling 400 is better than that on emissions.

New air filter, oil change, new plugs and gapped correctly, petrol system treatment/cleaner through the tank and a good blast at high revs to clear out the cylinders is what id do for mine but with an computer I'm guessing there's some emissions device not functioning correctly if your emissions are so high. I don't think a CAT is required for a 1991 car but removing it might make the emissions worse if there's an issue

no cat required on pre 1992 cars so non cat. test anyway (non cat test on pre 1995 if no cat fitted)
taking the cat off wont hurt and might help
was engine and O2 sensor hot enough? would expect it to sail through non cat. test

Thanks for your replies. I'm going to order a new air filter and some plugs.
Are delco plugs any good?

I will take a risk and cut off the ends of my existing cat and get a pipe welded up.
In response to the heat of the cat and sensor.. Yeah it would have been hot as my mot guy is a good drive away.
Could it be worth changing the sensor?

I'm also going to mention the car is really heavy on petrol consumption.

Well an air filter and plugs are going to help with fuel consumption but that may be why your emissions are high - is it a carb Or injection?

It's injection. Also it's an auto

Denso iridium plugs any good?

I would just use ordinary AC delco or alternative (Ngk etc)

Thanks. I've always chosen ngk so I will check a conversion chart.
Cheaper too.

got NGK in mine, ac delco are good too

If the car is using lots of petrol you have another underlying fault, Is the service engine light on? These cars tend to suffer with ECM and EPROM failure.