Code p1506 I replaced iacv and cleared code p1506. CEL came back same code, previously to that I cleaned mafs with mafs cleaner and removed throttle body and cleaned inside throttle body. Put it all back and now car idles high and need to get smog. Could it be possible that the t.p.s. may have gotten messed up when I cleaned it?

Over speed code need to replace the IAC,check for vacuum leak(s),clean the throttle body,disconnect the negative terminal to the battery for 3 minutes then reconnect that may clear the code

no clean it , use CRC Maf sensor cleaner, from 12" distant
carefully .
the maf can last the life of an engine, 300k, easy, if cleaned time to time... at the 30k service?
first google hit P1 means toy only code, (factory)
P2112 Toyota - Throttle Actuator Control System - Stuck Closed

Possible causes
- Throttle Body Plate Binding
- Faulty Throttle Actuator
- Throttle Actuator harness is open or shorted
- Throttle Actuator circuit poor electrical connection

The CEL should also be on in your truck. The Ford DTC (Diagnostic Trouble Code) P0171 is for bank one (passenger side) on 6 and 8 cylinder vehicles. There are also several differenct things that might cause this trouble code.

Disconnect the negative battery terminal.

1. One of the most common causes is a bad EGR differential Pressure sensor. It is mounted on the engine and is connected to the EGR valve via two rubber hoses. The sensor itself has an elecrtical connector, 2 hose fittings and is rectangular about 3" X 2". Replace the sensor if necessary.

2. Another cause may be a bad or dirty Mass Airflow (MAF)sensor. The MAF sensor is located inside the air inlet duct near the throttle body. The mount and electrical connector is outside the duct. The MAF is basically a hot wire in the airflow stream. It is fairly easy to clean. Disconnect the air inlet duct just upstream of the sensor. You will see a screen, and behind the screen is the MAF sensor wire. Use a good quality spray ELECTRONICS cleaner. Use ONLY electronics cleaner! Any other solvent may damage the MAF sensor. Spray the MAF sensor wire through the screen and let it sit for 5-10 minutes. Give it another shot of electronics cleaner and let it sit another 5-10 minutes. Reconnect the air duct and start the engine.

If the CEL comes on again, you may have to replace the MAF sensor. If that fails, it might be a vacuum or fuel delivery problem. Honestly, I don't know that much about how to correct vacuum problems.

God Bless and good luck!

DTC P1506 is set when the PCM detects the engine idle speed is greater than the desired rpm. This is most commonly caused by a dirty or bad IAC valve. Cleaning the throttle body will, most likely, cure this problem.

p1131 means that the bank #1 O2 sensor, the bank closest to the firewall, cylinders 1-3 is showing a lean mixture. Could be a vacuum leak, a misfire on that bank, an exaust leak upstream of the O2 sensor, fuel control or injector problem on that bank, a faulty O2 sensor, faulty PCM, faulty wiring in the engine control wiring harness.

P0171In the vast majority of cases, simply cleaning the MAF sensor does the trick. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling also Inspect all vacuum and PCV hoses, replace if necessaryCheck for a dirty fuel filter and proper fuel pressure

If you have a 2004 Heritage or Lightning, I would agree with richard3707 in cleaning / replacing the IAC. I would also suggest cleaning the MAFS ( Mass AirFlow Sensor ), and checking the rubber vacuum line elbow on the back of the intake as well.

The IAC is on the back of the throttle body ( need to remove the plastic throttle body cover to see it ).


The rubber elbow is just above it ( line running to the right in the picture ).
The MAFS is in the air filter housing, Take apart the air filter as you are replacing it, and clean it with MAFS cleaner ( or throttle body cleaner that is MAFS safe, it will specifically say on the can if it is ).


If you have a 2004 New Body Style, then this more than likely the Throttle position motor that is having an issue.
In the 3 valve motor, the engine is throttle by wire and the throttle is opened by the throttle motor, which sounds like it is not. You can try cleaning it, to see if it is just stuck on idle open setting.

You might need to simply disconnect the battery for 10 mins and do the usual like set the clock etc afterwards but although the ecu will have stored the code it should start from scratch, first doing a TBA (throttle body alignment) - lots of whirring and clicking, when thats stopped (ign on after reconnecting battery, dont start engine just ign on) the engine will be ready to start and hopefully since all is well the CEL(check engine light) should not come on. At worst, see if someone local has vag com or a hand-held OBD device that can reset the CEL and if it just comes back on, the fault is solid.

Did you mean you connected the original maf back up or a new one? If its the original and the light only appeared after disconnecting it, then the ecu mustnt have realised it was faulty, and only noticed when you pulled the plug, a reset should clear it no problem, but has you original fault returned after putting the maf back on or has it now gone away? Might have been a bad/dirty connection now made good, or if youve cleaned it, and its working fine, the CEL will be a dummy from the time it was removed so reset & your good to go! many a times while replacing the maf the wires beside the sensor gets disconnected or loose and this makes the problem.so check out the wirings. This will help. Thanks please keep updated. please do rate the solution positively .thank you for using fixya

Is this a 0174 code ?
You need to clean your MAF sensor with Mass air flow cleaner. Remove MAF from intake tube next to throttle body, inside looks like a honey comb, there is a thin wire, do not touch, just spray it clean, let it air dry.
Clear code, test drive

Check the MAFS ( Mass Airflow Sensor ) in the air filter housing for dirt in it. You can get MAFS cleaner at the auto store, don't use normal Throttle body cleaner / carb/chock cleaner on it.
It is in the housing, is a metal tower standing up when you look in the housing.

Also check the IAT ( Intake Air sensor ) to make sure it is clean. This is mounted to the left ( towards the throttle body ) of the air filter, should be pointing back or down.

When you reassemble the intake, make sure it is put together tight. Un-metered air should have set a CEL, but it might be boarder line to causing a problem.

If this is not it, next take the plastic cover off the throttle body, and check the vac line & rubber elbow on the back of the intake, and the line for cracks. This, if damaged, should cause a CEL ( lean indicators ).
Last while you have the MAFS cleaner, remove the IAC ( Idle Air Controller ) on the back of the throttle body and clean it. This can cause a stumble / erratic RPMs at idle ( has nothing to do with throttle usage ).


The MAFS and the IAT would be the best places to start.

Check vacuum hoses to MAP sensor. They can get porous after a while. Also check hose to EGR valve.

This code is for your electronic throttle control system it probably needs to be cleaned the butter fly sticks due to build up in side the throttle body clean with tooth brush and emission save throttle body cleaner clear codes and then dissconnect the battery for 3 hours hook back up then go for a short drive stop and go to reset idle control that should take care of this.