96 SC1 EGR Valve sticking?

[Karebear883]

I have been told that my EGR valve may be sticking, which could cause me to fail an emissions test. Can this part be cleaned so I do not have to buy a new one? If so.....how do I clean it? Thx!!!

[Cat Fuzz]

The EGR valve is just one small part of an emissions system. To give any advice on what might need to be fixed we would need to know the actual emissions numbers from the failed test and any SES codes there might be.

[Karebear883]

Hi, thx! I have not taken it for a test yet, and do not know the codes... When it was first hooked up to the computer I was told there was a problem with the EGR valve. I was told to take it for a tune up and return. I had the oil changed etc, and used the emissions additive. The "check engine light" comes on and off. The last time it was hooked up to the computer nothing came up. A few days ago the engine light went back on, I took it in, the computer indicated a problem with the EGR. I was told the valve may be "sticking" at times as it does not show up all the time. I was told I could replace or clean valve to save money?

I read the previous thread you had replied to Cat Fuzz, about gunk on EGRs, but do not know best way to clean...

[Cat Fuzz]

Well, there are several codes that have to do with EGR operation. Depending on the exact code, you may or may not need to clean it. It could be a problem with the control circuitry. The mistake a lot of people make is replacing a part that happens to be mentioned in a code description when it may or may not indicate that the part is bad.

Anyway, it's just a couple bolts to remove it. There is a port on the bottom of the valve that can get gunked up. Simply brushing it with a wire brush should do it. You'll also want to confirm that the passages in the engine are also clear.

It would help to know the precise code. If you don't know what the EGR valve looks like, look it up on a parts store website and it probably will have a pic.

[Karebear883]

Thank You!!!
When I stop in the garage tomorrow I shall ask for and write down the code(s). I will let you know the exact code prior to changing anything. You are correct, I should not assume it is the EGR itself. I do not wish to buy unessecary parts, especially if it is because a part(s) just needs some cleaning. I know where the EGR is (I asked, lol) but did not want to mess around and do more harm than good.

If I may ask another question.... I was "warned" by my friends husband that the gas cap is removed so it is tested, to ensure that it is working properly. The warning was to make sure the gas cap was properly put back on the car, as a loose or missing gas cap can affect the outcome of an emissions test? Is there any truth to this? I was told that a local garage had purposely "loosened or removed" the gas cap for the E-test so that cars would fail meaning ppl would pay for repairs. I cannot rely on the source, or how I can ensure that the gas cap is properly in place for the test.

[Cat Fuzz]

Gas cap: Yes, a loose gas cap can cause the system to detect a leak and set a code. Gas caps are now designed with a ratcheting mechanism build in. When you replace the cap after getting gas, you always want to tighten the cap until it clicks several times. A missing gas cap will certainly cause a fail result. A loose gas cap will cause a code to be set and anytime the check engine light is on, you won't pass an emissions test.

I don't know how emissions testing is done where you are. Is it a state run facility or is it like in California where you go to "certified" emissions repair facilities that are independently owned? The independents in CA can be crooked and they can easily get away with it.

We have state run emissions testing places here and they have always properly re-installed my gas cap after testing it. You can listen for the clicks as they re-install it.

[Karebear883]

Thank you again.... I am in Niagara Falls, Ontario and yes, it sounds as though it is the same as in Ca.. A garage has to be "certified" and there are "horror" stories about ppl getting scammed. I heard of someone having their car tested WITHOUT the gas cap on, and they failed. They (the emissions technicians) were switching her "defective" gas cap with a new one, leaving nothing on while running the test. Could that be the reason she failed? I emailed her earlier and she replied she passed everything except for the nitrogen or NO? area where she fell just a bit short. The technicians told her that having no gas cap on made zero difference in the outcome of the test, and told her to put high octane gas in and drive for a while, and she would have a greater chance of passing? I think she ended up changing both the EGR and CC!?, as that is what she was advised to do, although she did not have the repairs done at the place that did the test. Hence the warning I received about the gas caps, but if you ask 5 different ppl, you will get 5 different answers, and is hard to tell which is true or blown out of proportion. That is why I am "trying" to do all the necessary precautions b4 going. I regularily have my oil changed, tire pressure, etc checked, but never had to worry about an EGR valve, lol. I know enough not to allow the ppl doing the test to do the diagnostic and repairs, if needed. The problem is whether or not they will let you walk into the area closest to your car to check if the gas cap is replaced properly. Before I found out about the gas cap check, I was prepared to make sure it was on correctly before the test. Now I may not be able to see. When I went to a large national oil change place, I had already checked the condition of my air filter, among other parts, and asked a friend as well. It was still very white, with "some" fluff on it. I was advised and took the SHOP VAC to it, and it looks new. While my oil was being changed and I was paying for it, I looked over and asked the kid under my hood why he had my air filter out. He explained to me it was part of their service to inspect certain parts, and did I want a price on a new air filter, as mine needed replacing!? I asked him very politely to put the air filter back and kindly quit messing around with anything NOT related to an oil/lube/filter. This is the same kid who "broke the rules" and "allowed" me on the shop floor to look at my car while it was up on the hoist, as since the "boss" was not there he would allow me to leave the glass booth I was supposed to stay in. I wanted to see for myself how things looked underneath. He had already told me that the exhaust system looked fine. I had to point out the rusted hole in the pipe from the CC to the muffler, and the fact that the only thing holding my muffler on was the bracket, lol, as it had broken right off...Hmmm...lol...Yes, those parts were replaced later that day at my regular mechanics' shop, which is an hours drive away. I have him running my car thru the computer, and another friend closer to where I live also checks the computer which is why I know the EGR was only showing up sometimes.. I now have looked and seen there are at least 7 codes just naming the EGR, and will find out tomorrow what the present code is, if any...but I know where and how to check for gunk, thanks to you. I am curious though about my friends test, and if she would have passed the first time she went if the gas cap was properly ON the car...
thx again!
Kare

[Cat Fuzz]

This is difficult due to different testing procedures. In my state, 1996 model year and newer cars are simply connected to their computer to check for codes and emissions readiness. Just before this, they actually remove your gas cap and attach it to a gas cap tester to make sure it's working properly. The gas cap is always re-installed properly. There is no tailpipe sniffer test. They only do those for 95 and older cars.

From what I understand about your area, they do the sniffer test on all cars. They might also connect to a computer, I don't know. In my case, if the gas cap was loose, it would cause a fail because the computer in the car would sense a small leak and throw a code. In your case, if there is a sniffer only test, it would not cause NO to go up or cause a fail result. NO or NOX as it's more commonly referred to, is reduced by the EGR system. If the EGR isn't working properly, NOX goes up. There are other things that can cause NOX to increase but it is commonly the EGR that is responsible. So, sniffer only, probably did not cause a fail, sniffer with computer hooked up, could have caused a fail.

BTW, high octane gas does nothing for emissions or power output unless the engine needs it. Most engines do not need high octane fuel. The oil companies are happy to let people believe that "premium" fuel will always be better for their car when it is only needed by a few cars and gives no benefit to average cars. Fuel grades have nothing to do with the quality of the fuel.

Mainly, high octane fuel is for higher performance engines. These engines typically have a higher than normal compression ratio (the space left in the cylinder when the piston is at top dead center is less). When the air/fuel mixture is compressed too much under the heat of the engine, it can combust before it's supposed to and that robs power and can actually physically damage the engine. This is commonly referred to as knocking and pinging". High octane fuel resists this pre-mature combustion. That's all it does. If an engine has no problem with pre-mature combustion, it does not benefit from high octane fuel.


Back to the EGR. There are several things that can cause an EGR system to not function properly. The passages commonly plug up where the passage enters the intake manifold. The EGR valve could be defective or the wiring could be damaged. These are the most common issues.

[Karebear883]

HI,

I just came from my friends..... The only code that came up was P0341//something to to do with my crankshaft position censor and was told this would affect my timing,causing me to fail? Nothing came up with the EGR...but we did take it off and clean it...the valve moved easily..I was told the computer would only show the EGR valve as being faulty if it was stuck at the time the computer was reading it?..I was also told, again, to put high octane gas in...and it cd also be my CC? I am more confused now.

[Cat Fuzz]

Don't bother with high octane gas. There is a lot of misunderstanding, even from trained mechanics, about high octane fuel.

The code you got p0341 is actually Camshaft Position Sensor Circuit Range/Performance. Now, this usually throws some people off on Saturns when they go to buy a camshaft position sensor, the parts guy will tell them there is no listing for one. That's because Saturns don't have a camshaft position sensor.

Without going into incredible detail about how the Saturn's ignition system works, this code is usually fixed by removing the coils and the module underneath them and cleaning the "pad" that these are bolted to on the transmission with a wire brush and also making sure the module and coil packs are free of any corrosion. You will also want to check out your spark plug wires and the connection they go to on the coils and lastly, the spark plugs themselves could be the cause of the code. These commonly get a white build-up of gunk.

BTW, anytime the SES light is on it will be an automatic fail. If they hook up to the OBD port and even if the light is off, they see a stored code, it might also cause a fail. Also, they can see the readiness status of the various emissions systems. These monitors clear anytime the codes are erased and the car must go thru a "drive cycle" to reset all the monitors to an ok status. So, after you attempt the fix and erase the codes, you can't run right down to the testing place and expect to pass. You need to drive the car a certain way but usually driving it normally for a couple days will get it right. Just make sure to get it up the freeway speeds in the process.