I’ve replaced the iat sensor on my 98’ and it hasn’t fixed the code, has anyone else run into this issue? i’m guessing that it might be janky wiring or corrosion.

 

Welcome to the forum

IAT is a 5volt sensor like most sensors
It shares a common reference wire with other sensors, grey/red stripe wire
If you look at other sensors like, ECT, DPFE, TPS(throttle) you will see the same grey/red wire
Unplug one of these other sensors and the IAT sensor, and test OHMs between the two grey/red wires, should be 0 OHMs direct connection

With sensor unplugged you can also turn on the key and then test each grey/red wire for 5volts, but what you are looking for is the IATs grey/red wire a lower voltage than say the TPS grey/red wire which would cause that code, they should be exactly the same volts, 4.8v to 5.2v is OK as long as they are BOTH the same

If they are the same volts or 0 OHMs then problem is with the sensor or the solid grey wire(IAT return) to the computer
New sensor just means NEVER EVER TESTED sensor, not "it works"
You can test IAT or ECT sensors with OHM meter, they are basically the same type of sensor internally

IAT's Grey wire runs to pin 39 on the computer(PCM), you can unplug the PCMs large 104 wire connector on firewall and test the grey wire with OHM meter