Contour Enthusiasts Group Archives Forums Modifications Duratec Maintenance Intake Manifold Runner Stuck

K, well, my story might sound complicated but probably comes down to something simple.

About 2-3 months ago I had a new clutch installed in my car. When they installed it they found the VSS wires were melted onto the headers (I believe thats where). They had no choice but to break the wires to install it. So I ended up having a CEL code P0500 "Vehicle Speed Sensor Malfunction". So after a few months, I finally got the VSS replaced.

After it was replaced the CEL did not go out. I figured after a few days of driving it should go out, if not I'll reset it. Well it didnt go out so I brought it to Auto Zone and had them read the codes and clear them. But this time, they pulled codes:

P1518 Intake Manifold Runner Control (Stuck Open)
P0500 Vehicle Speed Sensor Malfunction
P1151 Lack Of HO2S21 Switch - Sensor Indicates Lean

So they cleared the codes. Drove it for a few hours and no CEL. Parked the car and next time I started it, it was back on. I brought it back and pulled only 1 code this time, P1518.

I have a few questions.

1. I shouldn't have a concern about the VSS CEL anymore right, it just didnt clear itself?

2. P1151 code did not come back after a few days of driving. Should I worry about it at all or was it just a fluke one time thing?

3. What is involved in fixing the Intake Manifold Runner Control? I'm not a mechanic so I know very little. Is there a how-to for this or should I just have someone who knows what there doing fix it?

I have a 98 Tour V6, non- SVT. Mine pulled a P1151 with a P0420. The dealer was concerned enough that he scoped it for me, reset the CEL and told me I had a bad O2 sensor (front upper). I replaced it and I pulled another code in several days, which the dealer again read for me. This time it read the code you had about the intake manifold being stuck. This time they replaced the catalytic converter under warranty, as I had just under 80,000 miles. I think the fact that with a new O2 sensor and the intake manifold code told them the cat was blocked - I don't know for sure but I wasn't going to question the free cat. (They even installed the rear upper O2 sensor, which I had purchased, while they were under the car doing the cat. Nice!)

What I am saying is if your Tour is under 80K have the dealer check the CEL code to see if you have the same problem I had. It is common enough that my dealer had all the parts in stock for the cat replacement.

On the flip side, I now have a CEL that indicates a lean condition; what could be a bad intake manifold gasket. That's aleast less expensive than a cat.

The IRMC (intake manifold runner control) is the device the controls opening the secondary butterflys in the intake manifold. Those butterflys are shut until the engine gets about 4000 RPM part throttle or 3400 RPM wide open throttle. It provides better low rpm throttle response and improved fuel economy whil allow for better performance during higher engine speeds.

The IMRC control box is mounted on top of the front valve cover, under the trim cover. It has a cable that attaches to the linkage on the lower intake manifold below the throttle body.

One of the common fauilures is that the cable frays and sticks and binds inside the housing. Sometimes the electrical motor inside the box fails or the electronics get flakey. The only real cure for any of this is to replace the IMRC control box since there is no practical way to repair any of these things. The box is a bit pricy so shop around.

There is a plastic clip that attaches the secondary linkage from one bank of the lower intake maniflod to the other that sometimes breaks so make sure it is OK before replacing the box.

A contributing factor to the box failing can be from sludge forming on the secondaries inside the manifold. It would be wise to clean this along with any other repair that you do. There is information on cleaning both from disassembly of the manifolds and from running cleaner into the manifold while the engine is running. I do the cleaning without disassembly and it works well for me but others say that the manifold teardown is the preferred way to go. Do a search and you should be able to learn more about both methods. The teardown method is in the FAQ section.

Good luck and let us know what you find.