Troubleshooting

[mobydick]

Can a code 33 cause a code 41/91?

What would most likely be the culprit of a 33? Bad position sensor?

Took egr valve off and cleaned valve and passages. Valve holds vacuum. Valve, position sensor, and control solenoid were all replaced about a year ago.

[gadget73]

not likely that egr not opening would cause the engine to show lean. a cracked vacuum line or a leak between the solenoid and the valve would cause it to not open. also, lack of vacuum to the solenoid would do it too. vacuum leaks could possibly cause the engine to show lean, but it would probably have to be a bigger leak than one one of those skinny lines could cause.

[mobydick]

not likely that egr not opening would cause the engine to show lean. a cracked vacuum line or a leak between the solenoid and the valve would cause it to not open. also, lack of vacuum to the solenoid would do it too. vacuum leaks could possibly cause the engine to show lean, but it would probably have to be a bigger leak than one one of those skinny lines could cause.

It's weird because I've had this problem before (the lean codes) and it went away. It idles good so I'm not sure where the leak could be coming from.

[gadget73]

the plastic tubes crack, and that multi-line connector thing leaks too. It may be leaking only on the EGR side, and only enough to make the valve not work. I got rid of that connector on mine. There were more patches than plastic line, and the connector thing fell apart when I tried to re-do the hoses. I ditched the smog pump a long while back, so I tossed all of the plastic hose and ran one rubber line from manifold to EVR, and one from EVR to EGR. I color marked them with red and green zip ties. Doesn't look entirely stock, but it works and doesn't fall apart if I sneeze under the hood.