Hey guys I was wondering if there was a ford mechanic that could help me out. I am working on a 2003 Mercury Sable LS with around 168000 miles on it. It was running like crap and would not go over 20 mph even with the pedal to the floor. It is throwing the code P1131 which Is a Bank 1 Sensor 1 sensor indicates lean code. So far I have replaced the pcv valve, hose, and other vacuum hoses which looked worn or cracked. I then took a can of starting fluid and put short bursts around all the hoses to make sure of no changes in rpms due to a vacuum leak. Then I put short bursts around the intake manifold and still no rpm fluctuations. After doing all this I decided to test the O2 sensors by unhooking the vacuum hose and spraying a burst of starting fluid into it. All sensors at idle were reading low voltage and when I sprayed cleaner into them they jumped up to .900-1.0 V. That leads me to believe that the O2 sensors are performing ok.
I hope I have given you guys enough information on this, I am not really sure where to start looking now, I have heard the intake gaskets but I would think that if I sprayed starting fluid around them and they leaked vacuum that I would have noticed a rpm increase.
Also one last bit of information. I have noticed that when in park it has a really rough idle, but as I give it gas (still in park) the roughness goes away. When I drive it though the rough idle continues until around 10 mph or about 1700 rpm then goes away after that, but yet I still get to 2300-2500 rpm and 25 mph and it will not go any faster or rev up any higher
one last thing before I quit lighting up the post. After I fixed the pcv valve and hoses I cleared the computer, before the clear, the codes were...
P1131- Lack of O2 sensor switches.. low input
P1336- CKP or CMP signal Malfunction
P0136- HO2S-12 Circuit no Activity
P1151- HO2S-21 Signal High Input
The last codes (136 and 151) were pending codes that I pulled from the computer.
Not sure if this makes any differences to the diagnosis but I figure anything helps.
Thanks again guys