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VW1300 · #9 10-01-2014, 10:09 AM

UPDATE: Last week I removed the EGR and cleaned it out - it didn't look bad, just a thin film of carbon on it. I hooked up my mityvac to it and was able to get the valve to open easily. I put it back on the car and before I re-attached the vacuum hose, I put the hose on the mityvac and started the car. I could see the vacuum pulling 20 inches for short bursts when it was trying to open the EGR. Finally, I cleaned out the little nipple on the intake crossover that leads to the MAP sensor.

I put it all back together and the code remained.

I did what worked the last time this happened and changed the filter on my EGR bypass. Lo and behold after 3 trips the code cleared.

My conclusions: the vacuum system and EGR lift sensor are working, else I would still have a code. I must be getting enough air into the intake when the EGR opens or else I would be getting a code. That filter must have been clogged enough after only a few months to prevent that from happening. I suspect that even when clean, it barely lets in enough air to satisfy the engine computer.

What remains to be improved - I'm looking for a better (higher flow) filter for my EGR bypass in hopes of improving airflow when the bypass opens. I also wonder if it could be a MAP sensor starting to fail, although that is a more expensive situation so I will hold off on that for now.