P1404 Code Can EGR Cause Misfire

I had another thread a while ago talking bout a blinking engine light which was explained to me as a misfire problem. It could have been caused by a lot of things so decided to by a scanning tool for my laptop to help diagnose the problem. It was a few weeks after that I received the scanner and I just read the codes, I only got a p1404 code which is a EGR pintle closed error. Now a few questions, could this cause the misfire and blinking light, it nearly stalled a few times and has been a while since it has really acted up??? and what exactly does the error mean??? Will removing and cleaning with carb cleaner solve the problem??? I have the Haynes manual and it appears to not be hard to remove, tips?? Thanks

yea those linear EGR valves can stick. the code means that when the pcm commanded the EGR closed the reported position wasnt what the pcm wanted and the condition lasted for longer than 20 seconds. so yes, next time it does it pop the hood hop out and tap on the egr with a ratchet or wrench or something and see if it stops doing it. ive had luck cleaning one of them out, they usually need to be replaced. the easiest way to test it is to use a scan tool that can command the EGR on. command it on and watch the actual positino in relation to the commanded position. if they dont match or take time to move into position its probably a good idea to try and clean it OR just replace the thing.

Flashing check engine lights indicate a severe misfire. When this happens, the cat converter can overheat and actually ignite unburnt fuel, causing a fire. In the process, the overheating can also destroy the converter.

a flashing light doesnt just mean a misfire, its considered as any condition bad enough to damage the converter. a misfire is usually the cause but not always. an egr related misfire could definitely do everything he has described.

Thanks a lot!! I attempted to pull the EGR off yesterday, I have the haynes manual and it wasn't the same set-up as illustrated, the bolts faced the firewall rather than straight up. With the abundance of room that these vans have at the back of the motor (kidding of course) my arms are a bit more scratched up then they were when I started. I couldn't get the darn thing completely out but did manage to get some carb cleaner into the port. There is one bolt which holds the flex pipe to the EGR and without room to get a decent wrench on it I could not get the bolt to break away. Needless to say the van ran flawlessly today and I am going to clear the code on the pcm and see how it goes. It looks as though I will be replacing the intake gasket this summer (very minor draw on coolant over the past year) so will hope this fixs the EGR problem until I have to rotate the motor ahead and do everyting at once. Got my toes crossed. What should my O2 sensors be displaying for watts or position etc, any ideas??

Your EGR valve should have just 2 bolts vertical, unless GM redesigned how the attached. I'm not sure what bolts you were removing that were horizontal facing the firewall.

The O2 sensor varies voltage between 0 and 1 volt depending on the oxygen level in the exhaust. The front sensor will fluctuate too rapidly for most multimeters to accurately measure. The rear sensor is just for measuring cat convert efficiency and responds slower then the front sensor. There should be a test procedure in your Haynes manual.

you dont have to take the pipe off from under the egr. you should be able to disconnect the wiring, remove two bolts and it might be somewhat stuck to the pipe. use a flathead and gently pry em apart. the gasket, if its in one piece, should feel and look like it has lead in it. if there isnt any major destruction to the gasket you can reuse it. those things are pretty tough and ive reused dozens without a problem.