Lack of power, help with error codes

[mallory]

Hi

Several months ago my 98 C2 cabrio developed a loss of power. Acceleration is poor and not as smooth as it should be and wont rev past 5000. Replaced spark plugs and coils but no improvement. Bought a durametric recently and it shows the following codes: p0150, p1128, p1130, p123, p1125 and p1689. Can someone help with interpreting this array of codes?

Thanks

[JFP in PA]

A quick caveat before we get started: Multiple codes can become a bit of an "Easter egg hunt" as two different codes alone may indicate two separate issues; but the same two codes appearing together may indicate a third and totally different issue.

That said:

P0150 indicates a short in the wiring for the O2 sensor ahead of the cat on cylinder bank 4-6.

P1128 & 1130 indicates that the O2 sensors have reached their limit of enrichment (overly lean conditions) P1128 for bank 1-3; P1130 for bank 4-6.

P1123 & 1125 indicates that the o2 sensors have reached their lean limit (overly rich conditions) P1123 for bank 1-3; 1125 for bank 4-6.

P1689 says the DME has a memory fault.

Obviously, you cannot be incurring both an overly lean and overly rich condition in both banks at the same time. I really think the main issue is the P1689 code. You can test the function of the O2 sensors individually just to verify they are OK, but I'd be looking at either a wiring issue (the P0150 code) to the DME or the control unit itself.

Edited July 22, 2011 by JFP in PA

[logray]

Sometimes I will clear codes to see if they come back... clears out the "old stuff" that might already be corrected and then the real stuff should trigger again.

The rev past 5000 is interesting, is yours a tiptronic?

[EleCTriCT]

Check mass air sensor and or vacuum leaks as well

[mallory]

Thanks for that guys, I'll start investigating further and let you know what I find.

Yes it is a tiptronic.