Ze’Neon has been plagued with an ‘intake air temp’ sensor problem for the last year. I unplugged the sensor, plugged it back in. It would seem to work for a while, then the check engine light would pop up. In order to pass the dreaded SMOG test out here in CA, I would have to have it working.
So last weekend we went to the junk yard – no luck. I called up a dealership and they had no idea what I was talking about. IAT? Intake what? It turns out that the IAT and the MAP (Manifold Absolute Pressure) sensor is in the same package on the Dodge Neon. I had to take it off the car in order to get the correct part number. When I put it back on, it was worse. She stumbled and wouldn’t idle. The rev limiter moved down to 4,000RPM’s. I just took a guess that the ‘lightbulb’ finally burned out. Welcome to limp mode.
So I get the $110 part special ordered for me today. Just need to plug it on and start her up. Wrong. Stumble, cough, hoark, stumble, die… Starter, stumble rev, rev, rev, die. Awesome. I start to track down the problem. At 9:00 I get to the end of what I can determine with two wires an LED and some electrical tape. We head up to the shop in LA to get tools – we head back.
Christine was trying to be as helpful as possible but it’s tough because it’s out of her hands. She can’t tell me what the ECU pinouts should be, much like I can’t tell her what her gel electrophoresis should look like. After poking the wires she made the sugestion that the connector itself was the problem. I had a feeling she was right but I had to prove it. I spent the last 10 minutes to midnight peeling the wires from the connector. Sure enough the MAP signal wire and the sensor ground were split apart. The copper had split on the inside of the wire. This happens when you pull on it with 60 pounds of force without unclipping the connector. What did mom say about pulling the plug out by the cord??
So, I have to re-splice some connectors, but we’ll be good to go this weekend. I will probably end up returning the $110 sensor. I almost dug into the jello under the ECU (or PCM if you’re from the before time) thinking it was a bad solder connection. Seriously, there’s jello covering the board – it’s creepy. 
wow, sounds like you went through hell trying to figure this out. good thin it was a simple fix before you had spent any more money or time on it.
Glad it’s fixed, Kris.
But what the hell is a “hoark?”
😉
hoark; verb. ho_orc 1. When the cat coughs up a giant house sized hair ball. 3. A dry heave that tightens all the muscles of the stomach, resulting in a ‘hough-Oark’ sound from the lungs. 3. The piston fills up with air and fuel and fires a few seconds later, rather then instantly. The valves are open and the mix burns in the manifold.
There you go.
– Kris