Howdy again guys!!

I know ya'll are going to think I have some run-down vehicles but I dont! Just a good run of bad luck here lately on vehicles. My wifes car is a 2006 Ford Focus its the 4 cylinder 2.0

At idle it seems to be "missing" the engine will sputter BAD and will eventual die out. The check engine light is on and is throwing a Faulty O2 Sensor before the Cat. Converter. I changed that out and the plugs and its STILL idling rough. You can keep it going by holding the brake and gas down, and when your moving it runs perfectly. Before I take this POS to the dealership to be worked on what else could it be????????


Thanks Guys!

When you replaced the o2 and plugs did you kill the keep alive memory on the pcm by pulling the negative cable on the battery for longer that 20 minutes? If you did then how did the plug boots look, cracks, distortion? How many miles what kind of service has been done lately? Did you put the exact same o2 as what came out of it? Same question about the plugs?

Do a compression test if all possible. Those engines have a history of the valve seats going to bad.

Does the engine sound louder than normal? Possibly a loud sucking noise from between the engine & firewall? my brother has a Focus & the PCV hose has had to be replaced twice. Same symptoms but different codes.

I would get on the Ford forum. Lots of issues with the Focus. I wish that I had done some research before I bought one for my son. You start reading up on them and you will want to get that thing fixed and as far away from a Focus as possible.

check for a vacuum leak

Like J- Spencer said. The usual suspect is the PCV hose. Rots at both ends so by the dealer hose.

+1 get you vin and head to your local Ford Dealer, This is common on the focus, just need to know if it is an SPI motor or a 4valve motor. Not too expensive of a fix. the elbow is hidden behind the motor where it leaks at.

that 2.0 sohc motor is the biggest POS to come from Ford in a long time! sorry 'bout that, but I have seen 5 otherwise good
motors just blow up for no particular reason.
Ck for vacuum leaks. 'specially that PCV elbow.
if the dtc is o2-lean, that's an immediate tip-off on the PCV.
good luck & let us know how it turns out
tight lines
-Brian

I agree! The DOHC engine is better and believe me it's cheaper if your looking for one from the junkyards.
Seen a couple SOHC where the valve seats came apart..

Sorry guys I didnt post back the results. Was the PCV Hose. Warranty(didnt know it was still active) covered it. Just had to pay the deductable. Now if I can only get my Chevy running. (still not getting gas to spray out of injectors..grrrrrrr)

ethier your not getting enough fuel pressure or you have no injector pulse.

hoggwild,

Now that you have it fixed I would look to dump that thing. When my son's went it was running perfect and never ever used a drop of oil. It just decided to [censored] out one day. Just another POS from Ford. I had 2 and I am now down to one.

HAHA dont tell me that Stump!!

Chris- I hooked up a test light to the connectors on the injectors and it had a steady charge no pulse...Assuming its suppose to pulse and not hold a steady charge?? Someone told me to maybe change out the injector wires...there known to go bad???

It is supposed to pulse while cranking/running.

Right, it is suppose to pulse. But when I hooked the test light to the wires it held a stead light not a "flicker"...well what does that mean and what to replace????!