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I have had a mechanic try to go straight to PCM module, he claimed the smog pump would not come on,(If comes on every morning when car starts up), I asked him about the egr valve, It could not have because the egr tube was clogged up, and the egr was stuck open. Unclogged the egr tube and got the egr valve to go up and down by spraying it clean with carburetor cleaner. I drove the car 50 miles after the car's battery had been disconnected for 15 minutes and reconnected. Check engine light did not come on. The next morning, I started car and let sit in place for 15 minutes. The check engine light came on. I went to autozone and used there scan tool. I got the following codes, that I did not get before.
PO150- O2 Circuit (Bank2, Sensor1)
PO155- O2 Heater Circuit (Bank2, Sensor1
PO136- [email protected] Circuit (Bank1, Sensor2)
PO203- Injector Circuit/OPen-Cylinder3
PO303 - Cylinder 3 Misfire Detected
PO130- O2 Circuit (Bank 1, Sensor 1 and PO141, O2 Heater Circuit (Bank1, Sensor). Please advise. No codes pertaining to egr valve or Smog Pump. 1999 E320 .
 

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For a start, check the cylinder 3 fuel injection connector. I remember I had to remove it to access the EGR.

Also get yourself a cheap code scanner. Else you will be going to Autozone many times :)
For the other codes, let me check :)

The chances are the mechanic did something to the wiring / connector for the PCM (ECU) when he was investigating the smog (secondary air injection ) pump.

Just because you do not have codes now for the EGR and the SAI it does not mean they do not exist. It just takes time, if the problems are not fixed yet.
 

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Discussion Starter #3
For a start, check the cylinder 3 fuel injection connector. I remember I had to remove it to access the EGR.

Also get yourself a cheap code scanner. Else you will be going to Autozone many times :)
For the other codes, let me check :)

The chances are the mechanic did something to the wiring / connector for the PCM (ECU) when he was investigating the smog (secondary air injection ) pump.

Just because you do not have codes now for the EGR and the SAI it does not mean they do not exist. It just takes time, if the problems are not fixed yet.
Thank you so much. I believe the mechanic popped open the
For a start, check the cylinder 3 fuel injection connector. I remember I had to remove it to access the EGR.

Also get yourself a cheap code scanner. Else you will be going to Autozone many times :)
For the other codes, let me check :)

The chances are the mechanic did something to the wiring / connector for the PCM (ECU) when he was investigating the smog (secondary air injection ) pump.

Just because you do not have codes now for the EGR and the SAI it does not mean they do not exist. It just takes time, if the problems are not fixed yet.
I believed that the mechanic popped open the case that contains the wiring because now they are exposed. I my belief he wanted to be PCM because that is one of the highest priced things to fix problem.
 

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Well then... I think he disturbed the wiring / connections somewhat for the O2 sensors and O2 sensor heaters from the ECU. It may also be the reason for injector issue, however make sure the injector connector at the injector is properly seated.

If he was trying to diagnose the issue regarding the smog pump, the ECU is usually not the place to start from. He should have checked the K40 relay module which is in the same place as the ECU.

The EGR valve / solenoid (not the pipe) cleaning is usually short-lived, and you would end up replacing the EGR valve + solenoid combo after some time.
 

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Discussion Starter #5
Thank you so much. I believe the mechanic popped open the

I believed that the mechanic popped open the case that contains the wiring because now they are exposed. I my belief he wanted to be PCM because that is one of the highest priced things to fix problem.
Also, The fuel injection 3 , If that is right behind the connector to the egr seems to work fine because I did not properly connect it and it was lose and the car ran rugged . Once connected properly, car runs so much smoothier.
Well then... I think he disturbed the wiring / connections somewhat for the O2 sensors and O2 sensor heaters from the ECU. It may also be the reason for injector issue, however make sure the injector connector at the injector is properly seated.

If he was trying to diagnose the issue regarding the smog pump, the ECU is usually not the place to start from. He should have checked the K40 relay module which is in the same place as the ECU.

The EGR valve / solenoid (not the pipe) cleaning is usually short-lived, and you would end up replacing the EGR valve + solenoid combo after some time.
Well then... I think he disturbed the wiring / connections somewhat for the O2 sensors and O2 sensor heaters from the ECU. It may also be the reason for injector issue, however make sure the injector connector at the injector is properly seated.

If he was trying to diagnose the issue regarding the smog pump, the ECU is usually not the place to start from. He should have checked the K40 relay module which is in the same place as the ECU.

The EGR valve / solenoid (not the pipe) cleaning is usually short-lived, and you would end up replacing the EGR valve + solenoid combo after some time.
Are the solenoids the 2 items to the left and right to the smog pump?
 

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They are not solenoids. They are combi valves (vacuum operated). Those are the ones that inject air from the pump to the exhaust manifolds. The EGR valve+ solenoid is at the back, where the EGR pipe is.

Somewhat people confuse the combi valves with EGR function, and they are not related. The EGR injects exhaust gas into the manifold, the Combi valves inject air into the exhaust manifold :).
 

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Discussion Starter #7
I took the egr valve and sucked in one of the vacuum lines it moved , but was very hesitant. Should the diapragm move up and down freely. I assume this car never had an egr valve change. It has 209,000 miles. Also, can the oil be a problem? i can see thru it ,but is dirty? Is the solenoid attached to the egr valve?
 

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Oil has nothing to do with the EGR.

If you do not have an EGR fault yet, what are you trying to do ? When you get a P0400 code, then there is something wrong with the EGR system.
 

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Discussion Starter #9
I initially started with a POcode indicating egr, then it starting showing smog pump code, Cleaned the egr valve and egr tube, un hooked the negative battery cable and drove the car 50 miles . No engine light came on, Next morning, started car and let car idle for ten miles, check engine light came on. All the codes came on when I went to autozone to use scanner.
 

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Discussion Starter #10
Now with a check engine scan tool I purchased from wal mart, the PO code 400 came up in addition to all the other codes ,
150, 130,136,155,135,and 141.
 

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After clearing the codes and taking the test drive, if you still have the same codes, I would suspect there is an electrical issue with the ECU to O2 sensor connections. No idea what the mechanic did, but if he injected any 12V on the O2 signal wires, the ECU would be gone. I would make sure that the ECU connectors are properly installed and there are no open or shorted wires where the connectors are.

Regarding the P0400, usually the problem is not the clogged pipe (unless it is close to 100 pecent clogged). Small amount of exhaust gasses are introduced, so typically cleaning a partially clogged pipe will not solve the problem.

More significant causes are the EGR solenoid electrical or mechanical issues. The solenoid controls the vacuum to the EGR valve and if it starts leaky or gets stuck, you will have problems.

Also check the MAP sensor vacuum hose. The EGR system uses the MAP sensor to check the change in the intake manifold pressure when the exhaust gasses are introduced to the intake manifold.
 

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Discussion Starter #12
Thank you so much will all your help. I am going to work on the car in a few minutes. It is crazy because I did change all the 4- O2 sensors before I went to this center. The housing was cracked open to the wires.
 
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