EGR valve I have cleaned the EGR valve and beleive it to be working ok, what makes this operate? still got misfire and smoke?

posible you have carbon loose at the egr valve when egr stuck you go to see smoke and mis fire same part store sel a egr gasket whit screen to solve the problem

Yes it can, at least on my 97 saturn SL2.
You can remove the EGR value and check for carbon built-up.

The carbon can build up on the intake valves and cause misfires.
The carbon lowers the octane level of the gas and also partly burns some of the fuel.

How I do a valve cleaning:

1. Buy engine de-grease for the outside of the engine
2. start engine when it is cold.
3. remove the pcv hose
4. spray into the throttle body for 30-60 seconds or stop when the engine chokes
5. turn engine off
6. wait 30 mins
7. start engine, white smoke will appear
8. have oil change since the cleaner will thin the oil

I use Lucas Upper Cylinder Lubricant to keep the valves clean for the type of engine below.
http://www.lucasoil.com/products/display_products.sd?iid=26&catid=8&loc=show

Start with a compression test. I suspect your # 5 cylinder has cracked rings.

saturn had a lot of problems with the coil posts getting rusty that will cause the misfire on cylinder number 3 and any skip will cause the random misfire see as one coil fire two cylinders the egr sensor is built into the vavle and try stick closed from carbon build up cleaning it will only putoff replacing it if it operates at all

YOUR EGR VALVE IS A PRESSURE FEED BACK ELECTRONIC VALVE.IF YOU USE A HAND VACCUM PUMP AND PUMP 5 HG TO EGR VALVE THE IDLE SPEED IS NOT SUPPOSE TO DROP AND ENGINE SHOULD NOT STALL OUT,YOUR EGR VALVE PAST THE VACUUM TEST.PROBLEM COULD BE PRESSURE TRANSDUCER OR THE EGR VALVE INTAKE PORT HOLES WHERE EGR VALVE SIT IS STOPPED UP WITH CARBON.CLEAN CARBON HOLE IN THE INTAKE WHERE EGR VALVE MOUNT TO.YOU CAN USE SMALL SCREW DRIVER OR PIECE OLD CLOTHES HANGER SEE WHAT HAPPENS.

make a coca can gasket and seal off the EGR valve completely or just leave the vac hose off if this works ok

If the car is thinking its lean, but its blowing black smoke then it sounds like its confused. Sounds like the o2 sensor is bad. How does it run when its cold?

if it is diesel i had the same problem plus poor mpg. it turned out to be the rubber pipe from the egr valve to the intercooler that was split cost at jag dealer £73.27 hope this helps. boovie

Clean the EGR valve seat. The EGR may have become stuck. A good way to check for vacuum leaks is to use smoke near every intake vacuun hose . And near the intake manifold. The valve will **** in the smoke. If you clean the EGR valve and it still misses. Replace it. The EGR can cause random misfire.

Try cleaning the EGR valve first



electronic Tempture Control
ECT sensor
symptoms
Potential Symptoms

Symptoms of a P0118 could include:

* Very poor fuel economy
* A no start condition
* Vehicle may start, but run very poorly, blowing black smoke, running very rough and misfiring
* Illumination of MIL
EGR valve

Usually a fault in the control circuit, will leave no noticeable symptoms other than the Malfunction Indicator Lamp (MIL) illumination. However, if the EGR control solenoid
is stuck open due to debris, etc. the code may be accompanied by misfire under acceleration, rough idle, or engine dying altogether.