Toyota 5SFE problem - help?

[Rallyfan]

Hello all,

My 2.2L 4cyl 5SFE Toyota is throwing code 71 check engine codes (EGR fault, exhaust gas too cold, EGR malfunction etc.). No other codes.

Previously, it'd thrown the same code, I swapped a vacuum line out for a new one, and it ran for 3 months without throwing the code again. However, now the code is back.

I'm not particularly in the mood to be pulling and cleaning EGR components, and was wondering if the EGR fault is harming the motor, or whether it is mearly a cold-start emmissions issue? If it's the former, I'll have to deal with it immediately; if it's the latter, I'll put it off a bit.

Following the lines (and of course without a book) I am confused whether the EGR deals with metred air - implying a fault could lean out the motor and result in a disaster, or rich it up and foul plugs etc., or something else I've not thought of - or whether it cannot affect fueling etc.

Any explanation and/or advise appreciated.

 

[sbc350gearhead]

If the EGR is stuck shut, then you can have pinging and detonation problems. If stuck open, it is essentially a vacuum leak, and can cause stumbling off idle, or at low rpm.

 

[Rallyfan]

Thanks, I won't put off repairing.

 

[edwardh1]

if easy to get off - take it off and clean it

 

[Rallyfan]

The EGR itself seems to work fine; there is a sensor that may be malfunctioning, and I'm pursuing that route now.

To me this implies that the car isn't running lean or rich, which is good, unless of coure the ECU uses the same sensor to meter fueling (not likely IMO, as there is the throttle body's sensors directly for that mass air measurement I guess, but then again I'm a newbie...).