Question about 1999 Pontiac Grand Prix

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EGR ports clogged

How can i safely clean the ports where my EGR valve sits on the manifold? it has a lot of carbon build-up and i am thinking it is restricting my flow.

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Yes i do have the CEL on.

Posted on Mar 12, 2009

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Are you getting a check engine light?

Posted on Mar 12, 2009

  • Clint Smock
    Clint Smock Mar 17, 2009

    What is the code number? But you can clean it with carb cleaner.



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Replaced egr valve and cleaned ports, giving same code.

When you say you cleaned the ports which ports did you clean.? These engines are very sensitive and do build up lots of carbon on the small egr vacuum ports. The focus here is usually the vacuum port inside the intake manifold that is behind the throttle body. Take the throttle body off and look inside you will see usually a big deposit of carbon where the port is to be. That needs cleaned. You also need to check the vacuum line that runs from the intake manifold over to the right strut tower. This goes to your boost sensor solenoid. Make sure that that line has good engine vacuum. If it does not clean that port as well. If that line is clogged I have seen the carbon get so bad that it clogs the boost sensor solenoid and the vacuum line after the solenoid. All of these ports need cleaned not just one.

May 02, 2014 | Mazda Protege Cars & Trucks

1 Answer

I changed all egr componet egr valve, egr selinoid, and sensor and check all hoses for clogs. reset check engine light still comes on after driving for a while


Aug 31, 2010 | Ford F-150 Cars & Trucks

3 Answers

I have a 99 f150 that has a code showing its p0402 egr valve excessive flow the engine is a 5.4 how do i fix it

First make sure all lines are connected to EGR , if not ,connect them if they are? Then remove EGR value and clean and reconnect.

Jan 24, 2010 | 1999 Ford F150 Regular Cab

2 Answers

I got 99 honda odyssey and p0401 code I clean the EGR but estl the problem

did you clean the valve or the ports. this code is for the ports clogging up. you need to remove the top of the intake off or plenum and you will see where the passage from the egr comes over. clean the plenum out where the carbon build up is and make sure air flows throughout. also blow air between the intake and the egr valve(remove the valve) and make sure there are no restrictions in that passage either. reassemble and you should be fine.

Dec 20, 2009 | 2002 Mazda Tribute

2 Answers

Egr problem , 1997 mercury mountaineer 5 liter. egr system not a dpfe system, no egr tube, ports into the intake elbow. replaced egr valve egr postion sensor, checked the egr selonoid for resitance showed...

Check the passages under the airhorn. When carbon builds up the diagnostic blames the EGR for not opening and throws a code. Actually there is no flow to the EGR because the port is clogged and the diagnostic measures the flow after the EGR.

They really needed to have a sensor before and after the EGR. Also remember to disconnect the battery for 10 minutes to remove old info.

Sep 24, 2009 | 1997 Mercury Mountaineer

3 Answers

Egr code put two new egr vlvs on it still get code

remove the egr valve take a piece of clothes rack or a tiny tiny screw driver carefully clean out carbon in the intake port hole on the intake.the carbon blocking off the egr it cant work properly.after cleaning carbon clean up the debris and go from there.

Jun 25, 2009 | 1997 Ford F150 Regular Cab

2 Answers

Code P1400 on a 1997 nissan maxima. help car wont pass inspection

P1400 on your vehicle is described as :Differential Pressure Feedback EGR Circuit Low Input You either need a new DPFE valve, or a new EGR valve. Both can be tested for functionality before replacing them both. EGR valve is more likely I think. Cleaning it may not improve its performance, but its worth a try. Also check the vacuum lines between the DPFE and EGR system. The EGR valve and DPFE are usually close together above the exhaust manifold/downpipe. you need service instructions to test these items, suggest you go to a garage really...

May 17, 2009 | 1997 Nissan Maxima

2 Answers

98 honda accord 0401code changed egr what else can I do ?.

remove the egr .clean the carbon out the intake where egr valve sits . use a small tiny tiny screw driver or old coat hanger clean out the hole then vacuum up carbon.put back egr valve.

Mar 18, 2009 | 2000 Honda Accord

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