I just bought a 1995 SOHC Neon. It isn't my primary car, so I'm not in a big rush to get it right. I've been driving a 1997 5sp SOHC for 2 years now, so I am familiar with Neons. The 95 runs fairly well, but it's showing 5 fault codes. I have a few questions regarding them. The codes are as follows:

1. P0134 - Upstream O2 Sensor Stays At Center
2. P0500 - No VSS Signal
3. P0172 - Fuel System Rich
4. P0138 - Downstream O2 Sensor Shorted To Voltage
5. P1294 - Target Idle Not Reached (+/-200 RPM)

1st question I have is: Does it matter what order the codes are when you retrieve them? Is the 1st code the 1st one that came in, and so forth?

2nd question is: Are P0134, P0138, and P0172 all related?

3rd question: If the speedo doesn't work, is it because of P0500, or is P0500 caused by the speedo not working?

I noticed a couple of vacuum lines in really bad shape, so I suspect that P1294 is being caused by that. Someone has the lines duct taped to try to stop leaks.

 

http://www.wjjeeps.com/faultcodes.htm

That's a list of all the codes and what they are.... and yes, the order in which you get codes can mean something. One wrong sensor or one wrong thing can actually cause several items to generate a code.

 

Check the wiring to both sensors and make sure they are OK. The fuel system running rich and the upstream O2 sensor can be related, and probably are.

If the VSS is out, then your gauages will not work.