: 1996 STS - P1406 DTC with bucking and hesitation



postman2000
08-20-12, 07:28 PM
Hello all, I was wondering if any one has experienced a problem similar to mine. On the highway sometimes the car starts bucking and hesitating under acceleration. If i ease off the gas pedal it helps but if I try to accelerate I can put the pedal to the floor and it will not accelerate at all..when this occurs I get a PC 1406 code which I looked up and found that it is a " EGR Valve Pintle Position Circuit" code..Any info or help would be greatly appreciated..:bouncy:

Ranger
08-20-12, 10:12 PM
Pull the EGR valve and clean the pintle valve. Make sure it moves freely and does not stick in the full open or closed position when you push on it. I think there is a tutorial in the Tech tips section.

postman2000
08-21-12, 05:56 AM
Thanks Ranger, I think I will do that..Do I need to clean the EGR passage ways on this year Northstar? If so do you know the best way to do it? I thank you for your reply..

MRneatfreak-
08-21-12, 07:48 AM
I had that problem all the time low or high speed on my 97 Deville right after I bought it. It was always in overdrive and under load, like not depressing the accelerator to downshift.

I ended up fixing alot of other problems and probably replaced some stuff that was still good. But ulitimately in the end I switched out the intake plenum for a used one. New intake gaskets, new throttle body gaskets, and a new fuel pump, I was also having a hard and long cold start problem, but I don't remember seeing any gunk built up in the egr.

You might check the tube going from the left bank manifold to the Egr to make sure its not restricted/crushed. It is on the back of the engine and goes down to the firewall area. Its a longshot.

postman2000
08-21-12, 11:04 AM
Yes! The car is having a starting problem! it actually sometimes backfires out of the intake manifold. So what exactly fixed your problem? Was it a new intake manifold or was it the cleaning of the EGR tube?

Ranger
08-21-12, 11:32 AM
Thanks Ranger, I think I will do that..Do I need to clean the EGR passage ways on this year Northstar? If so do you know the best way to do it? I thank you for your reply..
No. The EGR passages on the Northstar are large enough that they don't get plugged up like the 4.9. The problem is that the pintle valve can get carboned and start to stick so it does not completely close. Use a dental pic or such to clean the inside of the shaft (you'll see what I mean when you get it in your hand. Also clean the base where it seats and be sure to hold it in the upright position so as not to allow any solvent to run up into the "can".

postman2000
08-21-12, 06:01 PM
Thanks Ranger..I will clean the EGR valve and go from there..