X2 on a little more diagnosis. The EGR valve was open all the time which caused an "Insufficient Flow Detected" CEL(?) but the car ran fine because the ports were clogged, then when the ports were cleaned the car wouldn't idle because the EGR valve was still wide open. I think that's the chain of events.

There shouldn't be any vacuum on the valve at idle. If there isn't vacuum then the valve may just be stuck as Poorman suggested. In that case you may be able to clean it up and get it working again. If there is vacuum at idle then there's something wrong upstream: the EGR solenoid control valve or related wiring.

 

Replacing the valve altogether did not help. I still have the same problem and I have no idea what to do now.

 

I also now know that I have a exhaust leak where the manifold meets the down pipe. Dont know if that has anything to do with it.

 

So the "other" codes are gone now, correct?

The current ones were not there before, correct?

The put a timing light on #1 cyl and look for a good flash? Test the resistance of the spark plug wire. Did you touch the electrical connection to the injestor while cleaning the ports?

Any oil in the "plug tube"?

 

Lots of codes...ditto Poorman's question: What are the current codes?

Are you positive the exhaust leak is between the manifold and down pipe? I ask because an exhaust leak before the oxygen sensor can throw P0170 & P0171 fuel trim and system lean codes. Culprits are leaking exhaust manifold gasket, cracked exhaust manifold, or broken exhaust manifold stud(s).

5th Gen's usually don't throw a P0401 when the EGR ports are clogged up. That code indicates something wrong with the EGR valve, EGR solenoid valve, or the wiring or vacuum hoses attached to them. The factory service manual has step-by-step instructions to diagnose this code.

P1399 and the P0301 can be caused by vacuum leaks or EGR at the wrong time. It can also be fuel, ignition, or compression related.

Still true? This sounds like either a vacuum leak OR EGR open at idle.

Suggestions, in this order:

1. Fix the exhaust leak
2. Check for vacuum leaks
3. Check valve adjustment and compression
4. Troubleshoot the EGR system

 

Current codes are:
P0171, P0170, P0401, P0301, P1399, P0302 and P1300

Mechanic said that P0171 and P0170 is from the leak at the down pipe. I used the wrong nuts when I replaced the exhaust a week or so ago.

Exhaust is completely new from the manifold back. New plugs, cables and rotor. New belts, and air filter. Also I replaced the EGR valve yesterday.

How should I go about checking for vacume leaks?

EDIT: O2 sensors are also new.

 

A couple of ways have worked for me. A two-foot piece of 1/4" hose, one in stuck in my ear and the other end roving around the usual places: injector seals, intake manifold, various vacuum-operated valves/actuators. I've also used carb cleaner with a nozzle on the spray tip. The engine will speed up if the carb cleaner gets sucked into a vacuum leak. Keep a fire extinguisher at hand.

Exhaust leak is fixed? Even a very small leak before the O2 sensor can cause a lean CEL.

 

Problem solved. I swapped two vacume hoses a long time ago by accident while replacing the fuel filter and this caused the new EGR valve to stay open. Moral of the story, label hoses if you are going to undo multiple hoses.

 

Thank you for coming back with the answer. We've all done something like that before.....I have plenty of my own stories of just the same type of thing.