Zinik

iTrader: (1)

i had high NO # when my egr wasnt working. im sure that's most of the problem

Tkhang

Alright, so I tested out the EGR modulator and it works. The EGR works too..It's something else...I'm going to take off the Y pipe and give that a clean. Any other suggestions????

Ali SC3

iTrader: (10)

some people lower the ignition timing to pass the no, but that causes the HC and the CO to be significantly higher, and is a bandaid practice at the best. Ill give an example, a turbo sc300 running healthy with no egr whatsoever can easily have numbers lower than the max with a working o2 sensor and a working cat, obviously wont pass visual but that being said, unless the egr is faulty where its causing more emissions, your egr simply not working is not going to cause all your numbers to skyrocket. while emissions stuff helps, 90% of the battle is having a clean running engine and a working catalyst.

To me it seems like your cat is not catalyzing everything, see that 0.2 on the oxygen, even though there is no max for it, it tells you that you are not catalyzing everything, it should be a 0. It is also entirely possible you have a bad o2 sensor from the no being so high even with the ignition timing backed off.
generally when all your numbers are high, and you are on your original old cat, thats a big part of the problem. no amount of additives is going to get your numbers down enough if your cat is bad. Im not saying 100% your cat is bad but it is either that or an o2 sensor causing a bad fuel mixture that the cat can't handle, or even both. if your o2's are old there they should be replaced anyways.

6SOARER

iTrader: (20)

The EGR may be operating right but if you do not have sufficient vacuum, it will be as good as nothing. Make sure you do not have any damaged vacuum lines, and that the lines are hooked up correctly to your EGR components(EGR modulator/EGR valve). I seen this simple fix overlooked all the time.

How many miles are on your car? You may need a new CAT as Ali mentioned as well

Ali SC3

iTrader: (10)

I think new cat and o2 sensors. o2 sensors are really important for emissions.
did you know that bosch recommends replacing non-heatd o2 sensors every 30-50k miles.
If you are over 100k on the stock o2's your fuel mixture is not going to be good.

Tkhang

How can the cat go bad within a 3 month time span? and it's only be driven about 2000 miles since the last test. also another thing is that if the o2 sensors are bad, wouldn't it throw a CEL?

Ali SC3

iTrader: (10)

The cat is at 177k then it didn't just go bad, and i am not saying it is bad but if you have a bad o2 sensor that can cause a bad fuel mix which is very bad for the cat, so it could be bad.
do you know how old are your oxygen sensors are? If not you should replace them, the ones for our cars are a good deal online and its not that hard of a job, I would suggest starting there.
There is a possibility that alone may be enough if it happened recently.

Tkhang

Our cars only have 2 oxygen sensors right? and are they both the same?

Ali SC3

iTrader: (10)

yes there are 2 front ones and they are both the same and the ones that should be replaced to help the engine run better. if you have a cali model you may have a different kind of sensor so see how many wires are on the connector.

Tkhang

I believe its a one wire sensor.. I'll look into it more. but right now the car is in the shop. I'm having my mechanic look at it. Thanks for all of your advice and I will update when I find out my answer.

KahnBB6

iTrader: (5)

If you have an original Cali model you may also have a third O2 sensor after the first two. My '93 did. Unless that one isn't functioning at all, however, don't worry about it. The first two are the important ones.

Tkhang

Well, it was just the damn EGR. The port on the intake manifold wasn't cleaned out good enough so my mechanic took off the y pipe and gave it a good cleaning. It passed real good. Thanks everyone for their advice, couldn't of done it without you guys.