EGR Code 332 336 337 and vacuum leak problems

JNT

SCCoA Member
I'm having a hard time getting my EGR and vacuum problem resolved on my 94 SC.

I originally had a few EGR codes. I replaced the EGR transducer, and the EGR vacuum solenoid. This took care of all of the codes except for 332 insufficent egr flow. I then replaced the EGR valve itself. The code 332 is still there.

I seem to also have a vacuum leak. The gage reads about 12 at idle and drops to 0 as soon as the car is shut off. As soon as you get above a few pounds of boost the car bucks, for lack of a better word.

Is it possible that due to the leak there is not enough vacuum to open the EGR valve?

Thanks,
Joe
 
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might be a long shot, but maybe the whole tube is so gummed up with carbon and crap that the vacuum can tsuck enuf gasses thru it ?? :confused:
 
Thanks for the reply.

When I changed the EGR I cleaned out the tube as much as I could. I used carbon cleaner spray and pipe cleaners.

Joe
 
I'd try to find that vacuum leak first cause your car is stock right?if so you should have more than 12 inches of vacuum at idle.Find the leak first then it might take care of your egr issue if it doen't then at least you're only trouble shooting one problem at a time instead of 2.



Jay
 
I'd try to find that vacuum leak first cause your car is stock right?if so you should have more than 12 inches of vacuum at idle.Find the leak first then it might take care of your egr issue if it doen't then at least you're only trouble shooting one problem at a time instead of 2.



Jay

Yeah my car is stock. It does seem like the vac problem probably is causing the egr issue. I have replaced several vac pieces that were worn out. Tonight I'm going to check the vac from the box with a vac gauge. I think the next step may be sealing the IC tubes with gaskets.

Joe
 
Yeah my car is stock. It does seem like the vac problem probably is causing the egr issue. I have replaced several vac pieces that were worn out. Tonight I'm going to check the vac from the box with a vac gauge. I think the next step may be sealing the IC tubes with gaskets.

Joe



Yeah reseal you're i/c tubes and make sure you're intake bolts are still tight.You could search around for leaks with some starting fluid.


Jay
 
i'm pulling down 20 in/hg of vac at idle... but i have teh same insufficient egr flow code... :confused:

Differential Pressure Feedback EGR (DPFE) sensor signal to the Powertrain Control Module (PCM) did not change when the PCM output a duty cycle to the EGR Vacuum Regulator (EVR) solenoid requesting EGR flow. Possible causes are:
  • Icing
  • Obstructed EGR passages
  • Vacuum hose leaks.
  • Obstructed vacuum hoses.
  • Damaged EVR solenoid.
  • Damaged PFE/DPFE sensor.
  • Damaged EGR valve.
  • Damaged PCM.
Key "OFF".
Disconnect and inspect vacuum hose between EVR solenoid and EGR valve for blockage, kinks, etc. Service as necessary and reconnect after inspection.
Disconnect vacuum hose at EGR valve and connect hose to a vacuum gauge.
Rerun Key On Engine Running (KOER) Self-Test while observing vacuum gauge.
  • Is vacuum reading less than 3kPa (1 in-Hg) throughout the test (disregard DTC output)? If yes Check Vacuum Input to the EVR Solenoid
 
Well I just tested the EGR using the directions in the FAQ and it worked as described. The egr is brand new so I didn't expect a problem here. I took very little vacuum to open the egr, didn't even register on the gauge. I took so little vacuum that I don't think the vac leak I have would result in too little vac to open the valve.

I need to hook up a vacuum guage to the line that goes to the egr.


Joe
 
I Hooked up a vac guage to line going to the EGR. There is no vac at idle and when I open the throttle the vacuum does not increase at all.

I tested the vac line from the tee that feeds the egr vacuum solenoid and it measured 20 so it doesn't seem like a vacuum leak is the problem.

I already replaced the egr vacuum solenoid but it looks like that may be the problem.

Joe
 
Found a crack in the green line going from the vac tree to the EGR solenoid. I replaced this section of the line cleared the codes and went for a test drive.

The code 332 insufficient EGR flow is gone but I now have a code 337 EGR sensor above max voltage.

Joe
 
Code 332 has not returned but I'm clearing codes and consistently getting codes 336 and 337.

I pulled the octane plug to reduce pinging and prevent damage. Now I'm also getting a code 241. Does the lack of the octane plug trigger a code or this just a coincidence?'

Not sure why I keep updating this thread since I haven't had a reply in weeks.

Joe
 
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First thing to do is to remove the vac line from the egr and plug it and see if the codes return, don't worry about any other codes that set. Let me know what the results are. This is the 94 SC correct?
 
Yes its the 94SC.

Pull the vac line from the EGR then cap the vac fitting? Do I also need to cap the vac line going to the EGR?

Thanks for the help.

Joe
 
First thing to do is to remove the vac line from the egr and plug it and see if the codes return, don't worry about any other codes that set. Let me know what the results are. This is the 94 SC correct?

The only code this time was 332. I plugged the octane plug back in before driving the car again.

Joe
 
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