Code of 14?

14 - Map voltage too high or too low.

We never approve of throwing random parts at a problem, but in this case, the best suspect is the MAP sensor itself. Keep in mind, diagnostic fault codes never say to replace a part or that one is bad. They only indicate the circuit that needs further diagnosis. When a sensor or other part is referenced in the code, it is actually the cause of that code only about half of the time. First we normally do some voltage tests to check for wiring problems. If you want to pursue that, tell me what you find on the three wires at the MAP sensor's connector. To be valid, those readings must be taken with the connector plugged into the sensor. That means you must back-probe the wires through the rubber weather seals, alongside each wire, with the ignition switch in the "run" position.

Normal voltages are 0.2 volts on the ground wire, and 5.0 volts on the feed wire. The voltage on the signal wire has to remain between 0.5 and 4.5 volts, (approximately). It will be on the higher side, then drop to the lower side of the range when the engine is running. When a wiring or sensor defect occurs, it will send the signal voltage all the way to 5.0 or 0.0 volts. Those are the voltages the Engine Computer looks for to set this fault code.

GM had a huge failure rate with their MAP sensors in the late '80s, then they sold them to Chrysler. By now all of those have failed and been replaced. The redesigned sensor has been very reliable. For that reason, I would not hesitate to find a good used one in a salvage yard. Every engine size and every car model used the same sensor for many years.

This sensor measures intake manifold vacuum to calculate engine load, and therefore fuel needs. Its readings are also used by the transmission computer, when you have a computer-controlled transmission, to determine shift points based on road speed and engine load.

Chrysler is the only manufacturer that never needed a mass air flow sensor to make their engines run right. Instead, the MAP sensor has the biggest say in fuel metering calculations. It's the most important sensor in engine performance. One trick that's built into the software is when the computer detects a problem with the sensor circuit, it disregards the erroneous readings, then "injects" approximate values to run on, based on readings from all the other sensors, and the current operating conditions. That's why the engine can seem to run fine when the sensor or wiring has a defect. It won't run perfectly, but it will get you home.

The MAP sensor can also set a different fault code for a pneumatic problem, meaning something with the vacuum hose. In that case the sensor will still develop signal voltages that stay within the acceptable range. There's a different strategy the computer uses to know there's a vacuum problem.

Let me know what you find up to this point.