Hi all,

so I had my Ford Escape for over a year without any problems. For a few weeks I having major issues. It all started with a check engine light that was on and off for a while. Turns out to be misfire in Cylinder 5 due to bad spark plug. (Code 305 and 316) So I went to a mechanic to change the plug and coil since I was close by and thought its not a big deal, little did I know it will cause a whole line of problems.

Fast forward, he changes the plug and misconnected the wires ( at that time i didn't know) - He took an extended lunch break before getting back to solve the problem he caused. He couldn't figure it out, so I drove off angry and had to figure it out myself.

After connecting it the right way, everything was fine, but now I got a 430 code. Since I had to CA-Smog the car, I decided to put in some catalytic cleaner (Cataclean).

Next day code is gone, I drive it to get it smogged, pass, drive to work - after 5 miles the car starts stalling and I barely made it off the freeway to a parking lot. No power when the car is in gear, revs up slowly when in N or P - but not able to drive an inch. I let it cool for a few hours. When it was cold, you can move it a bit, but as soon as it’s up to temp, no more acceleration and power.

I start to diagnose it and eventually had it narrowed down to 2 things: Bad fuel (due to Catacrap cleaner) or catalytic converter.

To be sure I bring it to another mechanic, who confirms its the back catalytic (for sure). Got it changed - turns out, both front are bad too. He quoted me another $2200 to replace the two manifold cats, I denied as its a ripoff.

I replace the front manifold catalytic (bank 2) myself. It has improved a little bit performance, but it still has rough idle in waves.

There is a little hissing noise I can narrow down to the EGR. When I press on the EGR, it’s gone. But when I press it down, the idle doesn’t change or improves to proper idle.

What I’ve replaced so far:

• Back catalytic converter
• Front manifold catalytic converter (bank 2)
• IAC
• throttle position sensor
• hard plastic vacuum line that runs from bank 1 -> intake -> bank 2
• PCV
• rubber vacuum lines running behind -> EGR -> solenoid
• Spark plugs

What I’ve checked

• Mass airflow sensor
• EGR Solenoid
• EGR (holds vacuum, membrane pops back into position)
• Injectors resistance
• Spark coils resistance
• Cylinder compression (150 psi)
• resistance of the O2 sensors

Attached is a picture of the short term fuel trim.

What I’ve noticed is the long term in bank 2 is not like in bank 1

also Bank 2 sensor 2 is not like Bank 1 sensor 2.

I can’t really tell what it means. (please note that in the picture B1S2 shows peaks, but its all in the 0.76 range, it just zoomed in for some reason)

all these graphs are recored when at idle and warm engine.


Thanks and your help is appreciated!

 

Do you still have the P0430 code?

You can have multiple misfires without throwing a code, changing single plugs is never. good idea, might be worth putting in a full set of COPs - but I don't think that is your problem. I'd suspect:

Plugged rear manifold cat - the one you haven't changed (why not? Its likely as poor as the front one was)
Plugged rear cat (from the work on the failed front cat?
Damaged O2 sensors (maybe from the Cataclean???)

Is the ignition timing varying a lot at idle? If so that is another indication of misfires - that maybe too faint to throw a code.

I don't see a link from the mechanic's mis-connection of COP#5 and the Cat codes unless it appeared at the same time, or at the same time when you worked on it to rectify it. Either way I assume you have crawled over it looking for any wiring disturbed (although that should have given an open-circuit code on the O2 sensors). Driving with a serious misfire for any length of time isn't good for the cat and may have dropped it over the edge below the failure threshold.

 

Hi,

I don't get any codes right now. I changed now all spark plugs but not all coils. I've tested the coils and they show same resistance as the new one.
When the mechanic took off the Y-pipe you could visually see that the front manifold cat was broken apart. The rear manifold cat looked fine (not broken into pieces). Also it's a lot of work and another $400 guesswork.

I just know that I haven't got any P0430 code before, but when I connected it in the right way, the misfire code was gone, but P0430 popped up, so I concluded is was due his "work"

I want to be 100% sure before changing the rear catalytic, because it costs a lot and is also a lot of work getting it out there.
What I dont understand is why B1S2 is steady at 0.77V and B2S2 is going up and down - What is the right way S2 has to react?

 

B1 has the new cat and the steady sensor readings right?
B2 has the old cat and the varying reading? Not sure I understand why but there seems a link there. The P0430 is overall cat efficiency

If I've got it the wrong way around and B1 has the old cat but a steady O2 reading then that might indicate the sensor is just giving a static reading which is why the mixture is out...

 

B1 is closer to the passenger cabin, which has not been changed yet.
B2 is closer to radiator and has been change.

How is it supposed to be?
Sensor 2 going up and down in peaks? waves? or steady?
Can anyone say how a good Sensor 1 and Sensor 2 graph should look like - also for the longterm banks how it should look like?

I'm not 100% sure if the O2 sensors are good as they seem to be the original 14 year old ones.