The idle on my daughter's Protege is all over the place. Sometimes so low that it dies at stop lights, other times it is cycling up around 2000 and won't kick down. Automatic transmission.

Went to Autozone and got the following codes when they read the system:

p0070
p0100
p0010
p1195

We have tried basic tune up, new plugs, air filter. Have not changed the cap, rotor, plug wires yet, but this seems like a computerized fuel injection problem more than an ignition issue, so we are saving money to replace expensive sensors if we need to do that.

thanks in advance for any suggestions.

Mike

 

well i'm pretty sure there are no p0010, p0100, & p0010 codes. but your p1195 code has to do with the boost sensor (the sensor that monitors egr back pressure in the intake through a vaccum hose on the back of the intake near the firewall). usually the nipple that the hose attaches to the intake with is clogged & just needs cleaned out.
are there any vacuum leaks? it kinda sounds like you have one. is the intake boot split open? can you hear a whitsle or air noise from the engine?
lastly, is the coolant level ok? a slightly low coolant level will not hit the coolant sensor correctly & cause idle errors & driveabilty problems.

 

Thanks, the vacuum leak suggestion sounds right to me. The way it is all over the place certainly has the feel of a vacuum leak. We will work on that issue and look at that EGR vacuum line, the clogging problem at the nipple and see what happens, and check the coolant level aggressively for a few days of driving and see what happens.

I think once those are checked out, maybe it's time for another trip to Autozone to read the codes again.

We are thinking about taking it to the dealer to have the codes read and get the dealer evaluation on what needs to be done, but we are worried that the dealer might be an expensive trip and might simply tell that for $1000 the car can be all tuned up. Car isn't worth much more than that tuneup, but it's a great little car when it's running right. Thanks again. for your suggestions.

 

P0010 = Camshaft Position Actuator Circuit. Not sure on this one. Still learning. => MIGHT be related to your camshaft position sensor. If it's unplugged, that could lead to problems for the engine knowing when to fire the fuel injectors and what not.

P0070 = Ambient Air Temperature Sensor Circuit. Check to see if it's unplugged, or if the wires going to the plug are damaged somewhere. If not, you may need to replace the sensor.

P0100 = MAF (Mass Air Flow) Circuit Fault. Either your MAF sensor could be shot or someone left it unplugged. Could also be faulty wiring.

P1195 = EGR Boost Sensor circuit fault, as woodurb69 said. The nipple on the manifold may be clogged, but also note that between the boost sensor and the line to the manifold, there is an electronically controlled vacuum solenoid type valve. When I performed a decarbon service on my '98 protege (mist a chemical into the intake to clean out all the carbon and fuel deposits in the manifold, on the intake valves, and in the cylinders), I threw this code. Turns out some of that gunk somehow got to the valve. Replaced it, all was well.

With the MAF sensor and the Ambient Air Temp. sensor, both of these are attached to your air filter box assembly. If anyone ever changed the air filter and unplugged them to get them out of the way, but forgot to plug them in, then what you get is essentially a car that has no clue how much air is coming in. If the sensors are going out, they may feed information intermittently, or they may just feed incorrect information. In either case, this will severely affect the fuel/air mixture, and make your engine run terribly.