[Mergatroyd]

1998 Camry 2.2. Today the CEL comes on, car is running great. Pull into Advance Auto and this store does check the codes. Their code reader looks to be new. Fellow inputs the year, make, model, engine, the code reader does not post a number but "Possible insufficient exhaust gas recirculation".
So I guess the code would have been P0401.
My knees need replacing and doing the car repair myself is very difficult at this time.
I found an excellent thread on this forum from 2009 about this problem. The parts costs then were much higher than I am finding today. YouTube has videos too.
My area does not have emissions testing for annual inspections-- and my next inspection is due about 11 months in the future.
So if I just drive it with no repair, what are the consequences? Any permanent damage?

 

[Blackness]

The EGR system cools the combustion chamber to reduce NOX. With the EGR valve stuck open you will run lean... if it's full on open all the time you will stall/be unable to start due to being waaay too lean. If the EGR is stuck closed, or simply blocked off, no cooling happens and your chances of making NOX increase... there is technically no engine damage that can occur by removing/blocking the EGR.. man older engines had no EGR system and NOX numbers were still 'normal'...

 

[Mergatroyd]

Wonderful response. So there is no evidence at all that mine is stuck open. No symptoms indicating such and the code reader does not so indicate.
I recall that EGR appeared on US cars beginning in 1973. Fuel mileage and performance were terrible for the rest of that decade.
One possible downside to just leaving it as-is would be that if additional things occur that would trigger the CEL, I would be unaware of those while the CEL is already showing. And some of those could be damaging to the car.

 

[Mergatroyd]

Today driving the car (see the first post) and the CEL disappears. No change in the running of the car. Drove about 18 miles of suburban roads. Stop sign and I turned left and full throttle up a slight grade-- the CEL lights up again.
My guess is that carbon lodged and blocked the passage, temporarily moved out of place and then moved back to blocking position.
So, does the CEL code disappear as soon as the condition is corrected or or must the module be reset by exterior means?

 

[Stillrunning]

With blocked EGR you may get some pinging. Keep a listen.