Replace Intake Manifold Gasket

Hello All, I'd like to thank these forums as I was able to look through old threads and solve the problem that my cougar was having with its Transmission Range Sensor. But this time, I'm having trouble and would like to hear some opinions.

Stats:
Mercury Cougar 2000 2.5L
78,000 miles

Background Info:
Check engine light is on, received codes p0171 and p0174.
Cleaned the Mass Air Flow Sensor, Checked all four O2 sensors - none of this removed the check engine light.

Current Info:
Bought a can of carburetor cleaner and sprayed the 6 bolts holding down the Intake Manifold. The 3rd bolt on the top row, when sprayed, the engine instantly became quieter.
This leads me to believe that the top rows Intake Manifold gasket needs to be replaced.

My question is thus, how to I go about replacing the gasket?

I've read that it is a somewhat easy job but can be very time consuming.

Thank you

Removing the bolts that attatch the EGR valve to the intake will be the worst part. If those come out without breaking the rest is easy. The two vacuum lines that go into the top of the intake near the throttle body are removed by pressing the plastic collar down while pulling on the tube. The rest is just clamps, nuts, and bolts

Stats:
Mercury Cougar 2000 2.5L
78,000 miles

Background Info:
Check engine light is on, received codes p0171 and p0174.
Cleaned the Mass Air Flow Sensor, Checked all four O2 sensors - none of this removed the check engine light.
Thank you



Fixing the problem will not remove the "check engine light" right away. this is OBDII. The car must perform the readiness monitor 3-70 consecutive times without failing or any other codes being thrown before the code will be reset AUTOMATICALLY.

On the other hand, after you make a repair, simply disconnect the battery, touch the cables together, and reconnect. PCM should clear the codes, MIL light, and will then start over with its Drive Cycles. Once it decides to test the component thats failing again, will it illuminate the light if the component test failed TWICE for a type B, or ONE for a type A.

I dont have my recourse manual with me, but what are the descriptions of those codes?

They are lean codes for both banks. Most common issue on those is leaking plenum gaskets

They are lean codes for both banks. Most common issue on those is leaking plenum gaskets

yah, that or a vacuum leak somewheres.

Once you repair it clear the PCM as described and the MIL should stay off till something else goes wrong. Being as it's a Ford product, expect this sooner than later.