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I have a 2003 Ford Escape 3.0L,I had a CEL light for a P0430, Catalyst System Efficiency Below Threshold (Bank 2), and my RPM’s would not go above 2500 unless I floored it. I believe this was from a bad coil and vacuum leaks I inherited with the car.
I was confindent I had a clogged Cat so I purchased a tested used part due to budget, pulled it off and replaced. After clearing the CEL, I started in upper and it sounds good but both B1S2 and B2S2 02’s are reading a consistent .750mv. I do not think is normal, thought it was supposed to be around .45mv? Any ideas as to why both banks are reading consistently rich?
Both upstream o2s seem to be fluctuating nicely, starting to think i have a fuel delivery issue due to both banks being rich. Any thoughts would be appreciated.
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see if this helps.For the p0430 the o2 is doing its job reporting
that the cat is not doing its job cleaning up. Does the vehicle have
more than one cat?http://www.justanswer.com/ford/63w8h-ford-escape-xlt-scan-03-ford-escape.html
Yes, there are actually 3 on the v6 escapes. Two are built into the exhaust manifolds on each bank and one under the middle further down the exhaust. I replaced the cat already but haven’t taken it for a test drive yet. When I hooked up the scan tool the live data was showing both banks were around .750 mv on the downstream o2. They decreased when I snapped the throttle then settled back at .750mv.
I watched this video several times and was part of the reason I decided to change the Cat in my car. I do not have a thermal reader yet but I do have a scanner. I just took it out for a quick test drive today and at idle my car read:
LTFT = -3.9 on both banks
STFT = moves between 2.9 and -3.9
B1S1 = moved between .2 & .8 volts
B1S2 = stayed rich around .700 -.750
Same for Bank twoWhen I had the rpm’s between 1500-2000 i had the following:
LTFT = -3.9 on both banks
STFT = moves between 2.9 and -4.9
B1S1 = moved between .2 & .8 volts
B1S2 = moved more lean around .3 volts and went straight back to .7 volts
after I let off the throttle
Same for bank twoSeems like only the downstream O2’s are out of acceptable specs, and I also noticed a slight rpm rev after I let off the throttle. If this a clear sign of something please let me know. If you have any questions i will be happy to answer.
You may have other issues besides a bad catalytic converter. Honestly I’d have to look at the results myself to determine if it seemed normal or not. It does seem like you might have a bad cat however but I think you also need to address the rich condition.
The infrared thermometers aren’t that expensive. You might consider picking one up as it can be useful for many things.
http://www.jbtoolsales.com/general-tools-irt207-infrared-thermometer/#oid=1002_1
This way you’ll know for sure if you have an issue with a catalytic converter or not.
The front bank exhaust manifold with the cat built into it has been replaced (rpms are back as well, see above), I took it out for a drive and noticed that whether at idle or cruising at 60 mph, both down stream 02’s are reading rich around .700-.750 but when the throttle is snapped or even slightly increase the o2 instantly drops to below .250 volts and when release they jump right back to rich or .700-.750. See video for live data of O2 B2S2 while at approx. 60mph.
I am working on getting a thermo gun but I feel like i may have a vacuum issue again. When I raise the throttle when parked I think i am hearing a vacuum leak but only when rpms are increasing. I do not notice any misfiring.
If you’re trying to diagnose an engine issue you should be paying attention to the upstream sensors not the downstream. You really only watch downstream sensors when you’re monitoring your cats. If you have a bad cat due to loss of catalyst in the cat. Your down streams will follow your upstream sensors on a plot graph. You need to use a back pressure gauge or ir gun if you looking for a clog. What is your main concern. Re sell the used cat and buy a back pressure gauge until you do that you can’t assume a back pressure issue is because of the cat and you also can’t assume you even have a bp issue until you check.
I already replaced the bank 2 cat with the used one I had purchased, due to lack of power under load, the downstream o2 sensor was almost identical to the upstream, and the CEL for P0430.
The escape is seems like it is running great but now both downstream 02’s are reading extremely rich under idle and extremely lean under load.
The upstream o2’s are reading normal at idle and changing rapidly from .1 to .8 but under load i did notice a change, the reading dropped the max so .1 to .650, but once the load was release it went right back to normal.
I do not think my cats are an issue at this point, I am thinking fuel system related, dirty or bad MAF, or some type of vacuum leak under load. I am concerned that the rich condition at idle will melt another cat.I think we should clarify, the rear O2 sensors are running ‘slightly’ rich. It may be normal. The fact the the voltage remains relatively steady means that the cat is most likely working as well as the O2 sensors. In fact what you’re looking at could be normal operation. Try not to ignore the evidence and jump to conclusions if possible.
The LTFT on both banks are reading slightly rich (-3.9) at idle and (-4.9) under load. STFT seems to be staying +/- 5. The lower/downstream o2’s are reading very rich at idle (above .700volts)but then goes up and down rapidly under load, see video in previous post. I do not think that is normal?
Also if anyone has any info for PID data on a 2003 escape showing acceptible readings/ranges, it would be greatly appreciated.
Thanks!
Stop looking at your lower o2’s If you are worried about a rich condition you need to be looking at your upstreams, which i have stated above. I don’t think you’re really sure what you’re looking at. Your downstream o2’s are for monitoring your catalyst. Your upstreams are for monitoring your a/f o2 switching. If you have .1-.9 and are rapidly switching on your upstreams then you are fine. If it is sitting at a higher voltage like .7/.8/.9 consistently then you have a rich condition. Your lower o2’s should not be fluctuating as much, they should stay steady, but will change. You CAN NOT base rich or lean condition on your downstream o2s whatsoever for the simple fact that the gases have already passed through your catalyst and changed from when they were in the engine.
If your upstreams are switching then I think what you’re looking at is a normal condition. If your upstreams are showing high voltage it’s rich, low voltage, lean. I don’t mean just showing, I mean staying there and hanging out consistently.
Ok, I am picking up what you are putting down, I am just concerned with melting a cat. If the lower o2’s are reading rich does that mean the cat could be overheating from fuel being dumped? From what I read from several sites the lower o2 should be around .450 volts and mine are not even close. Something is not right here.
I have two videos of readings, one at idle and one with raised rpms, not sure if this helps. I did notice the engine load % drop when raising the rpms, thought it should move up not down. Also if you look at the both upstream o2’s bank 1 seems to be changing slower.https://www.youtube.com/watch?v=_S-Dt_wQXdg at idle
https://www.youtube.com/watch?v=8yerSUrNgIk with some throttle
I never say always but I think you will be okay. If you are concerned about a rich condition your front o2 would show it. If fuel was being dumped out of your engine into the cat, FRONT o2s would show rich. The normal situation of this happening is with a misfire. Air and fuel is being pumped into a cylinder that for some reason can not ignite it all the way, thus raw fuel being pumped into the cat. Now this being said your front o2 sensor would see this happening BEFORE it enters the cat and say hey something isn’t right here. So if your upstream o2s are not showing rich which they aren’t then there is no raw fuel being read as it comes out of the exhaust manifold otherwise it would show via the high voltage. Now unless your car is the first one on planet earth to have a fuel line connected to the cat, after the upstream o2 sensor bypassing it then there is no way fuel can get in without your upstream o2 seeing it first. A cat is a chemical reaction using catalyst such as platinum and gold to pull hydro carbons out of your exhaust gas as it passes through. In other words I think you have nothing to worry about. There are 4 things in my opinion you need to know about your catalyst system. 1. Why it’s there 2. How it works. 3. What role it plays with oxygen sensors 4. Why and how do they fail. If you apply those too your situation you’ll see why I think I you’ll be okay. I never say 100% unless I diagnose it but that’s my 2 cents. Good luck brother keep us posted.
P.s. props for supplying us with good information for us to work with. I.e. scanner info
if your engine is running rich the upstream O2 sensor would spike over .8V and it is completely normal for upstream O2 too spike from .2 .8 now if upstream would spike up too above .8 more like 1.0Vs then i would be concerned about a rich condition caused buy the engine… now as for your catalitic converters it is ALSO important too note that during start up the engine may run slightly richer, if you are doing these tests just after start up, it is completely normal for a downstream sensor too detect over .7V because the engine naturally runs rich for start up condition, ideal Voltage condition for downstream o2 should be somewhere between .4 and .7V any more or any less then i would be concerned about a lean condition…
ShopTech is right if you want too test for a rich condition you need too pay attention too upstream… and upstream once again appears normal.
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