Check engine light

Have you had the vehicle scanned for codes?

Lincoln town car paper clip code trick1

Lincoln town car paper clip code trick2

Once you have the codes, you can look them up on the web. Just do a search ' 94 Lincoln town car code.....' Just plug in the code(s) number.

First of all, why was the O2 snsr replaced?... Check Engine light? What DTC (diagnostic trouble code) did you find stored in the ECU (Engine Control Unit)? The drivability you seem to be describing can have multiple causes -- faulty sensors, malfunctioning computer, clogged catalytic converter, leaky injectors, vacuum leaks, etc.

Ok... this is gonna take some time. The 04 Santa Fe came with 3 (three) different/possible engines -- the 4 Cylinder 2.4 lit, the 2.7 V6, and the 3.5 V6. Only the 2.4 (4 cyl) and the 3.5 V6 are equipped with EGR. The 2.7 does NOT have EGR. To answer part of your question, the EGR system on the 4 Cyl is known to develop restriction(s) in the EGR port (from the # 4 cylinder exhaust port to the EGR valve at the intake manifold). This port travels through the head (front to rear, i.e., Left to Right when viewing the engine from the transmission end). This port cannot be seen at the # 4 cylinder exhaust port unless you remove the exhaust manifold.

It would be very helpful if you could provide more detailed/specific information regarding the drivability issue & what/which codes were found related to the Check Engine light.

o2 sensor: or you have stopped up injectors or a vaccum leak or egr valve sticking

Causes A code P0401 most likely means one or more of the following has happened:

• The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced, this is the common cause
• There is a blockage in the EGR (tube), most likely carbon buildup
• The EGR valve is faulty
• The EGR valve may not be opening due to a lack of vaccuum

Possible Solutions In fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.

• Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
• Clean out the EGR valve and/or tubing to remove deposits
• Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
• Replace the DPFE sensor (with a good quality / OEM one)
• Replace the EGR valve

Symptoms There may be no visible symptoms to the driver. Poor fuel mileage, possible misfire, depending on O2 sensor position when sticking.
Causes A code P0136 may mean that one or more of the following has happened:

• Faulty O2 sensor leak in exhaust close to O2 sensor, faulty O2 sensor is the common cause.
• Short to voltage on O2 signal circuit
• Open in circuit resistance caused by corrosion in connector

Possible Solutions

• Replace the second oxygen sensor on bank 1
• Repair open or short in signal circuit
• Clean corrosion from connector

Lean condition causes go from a clogged fuel filter to a vacuum leak to a weak fuel pump.Lean means there is not enough fuel for the combustion chambers.check these items:)

Did you re check for new codes after o2 replacement? Does the idle hunt (up and down)? Have someone check the EGR valve.

HI, the best thing to o in this situation is to go to auto zone or your dealership for a diagnostic run. this will check the cpu for faults and it will describe the problem as well. after the diagnostic cpu is done, it will reset the check engine light. it will turn it off. I suspect maybe a O2 sensor or EGR valve malfunction.

Hi, the best thing at at his point is to get a diagnostic review by using a diagnostic computer at the local dealership or garage. Once your car has been diagnosed, you will be able to reset the cpu and the light will go off. its probably just an O2 sensor or egr valve needed.

replace the vsv that has the vacuuum hose running from it to the egr valve

Absolutely a bad o2 sensor can cause problems with performance. If you replace one it is highly recommended to replace both or all four depending on your vehicle. If one o2 sensor is making your vehicle run rich you will burn more fuel and in return increase the amount of carbon or unburnt fuel if you will in your egr valve you could probably get away with cleaning it but I would recommend replacing it, it will save you from having to pull it off again. Check your catyletic converter because long exposure to carbon will mess it up.