Civic Chokes at Low RPMs

My 03 civic will drive fine when the engine is cool. But after getting off the highway, or running it at higher speeds, when I put it in gear, any gear, it will start choking and bucking like its running out of gas. Once I get it above about 2000 rpms, the choking stops. The read out said it was the egr valve at first, we had it cleaned, but it didn’t fix it. The readout now says recirculation insufficient or something like that. I’m wondering how serious this is, and if I should be driving it. Thanks in advance.

If the check engine light isn’t flashing at you then chances are you’re not going to do any real damage. However, you obviously need to get to the bottom of it and restore performance.

Find out what the exact error code is - the format is “P1234”

Presumably it is an insufficient EGR flow code - but there are lots of EGR system codes and what you should do can vary a lot depending in the code. Its also the case that your symptoms would most likely come from excessive flow - rather than insufficient flow.

Who is doing this diagnosis? The EGR valve itself is only one part of an entire system - so the whole system has to be checked, not just the valve.

EGR valves are cheap. I would have replaced it instead of cleaning it. Try replacing it now to see if it gets better.

You might also consider having the throttle assembly cleaned, which you might be able to do yourself with a can of carburetor cleaner.

I’m going to disagree with Bocephus Moonshine. First, I don’t think of EGRs as being cheap. Obviously it depends on your definition of cheap, but they are often not cheap in the context of my budget.

But the bigger issue not about that part. This leads to “throwing parts at problems” which quickly gets expensive even if the individual parts are cheap. Today the EGR valve is your “guess.” Tomorrow its the vacuum solenoid. The next day its the pressure sensor…

OK, so an EGR valve for a 2003 Civic can be as high as $125, but I am used to them costing $15 or less. I stand corrected.

If the part was $15, I would definitely be willing to throw a replacement part at this problem, just like I would try a new radiator cap for certain cooling system problems, but if the replacement costs $125, I can see why it was cleaned and not replaced.

Are your O2 readings correct? It could be a overlean condition. Engine water temp can overlean as well. It maybe just below error code level on each of these sensors. Water temp is cheap and quick to test and replace. O2 is a bit more but an active test of performance can tell more. Egr codes are driven by the O2 sensors given certain conditions the egr is feeding exhaust back to moderate the O2 controller.