Intermittent P0153 Code Question

I've been getting an intermittent P0153 code and had pretty much decided to change the upstream sensors...BUT.. this past week I haven't gotten any codes, P153 or otherwise, even after today putting my '98 Windstar through a bit rougher driving than I normally do (rapid accelerations, up and down hills pushing a bit, plus highway mixed with stop and go driving for about 20 miles).

Also, I'd previously had the code come on, then turn itself off for a few days, then come back on, a few times.

What I'm thinking might be the way to go right now, and I'd appreciate any advice, is to follow the guidelines I've recently seen here for checking out/renewing a vehicle with 140K miles on it, which mine nearly has. This vehicle also wasn't driven a lot recently, before I bought it.

I thought I'd first check the vacuum system, replace PCV, EGR, air filter etc, then have the oil examined to see if there's any antifreeze getting in there, then do the Bars Leak treatment. This all before maybe replacing O2's unnecessarily.

Am I on the right track here?

Hello Michael.

Yes you are absolutely on the right track! About fixing it yourself.
But. The car hasn't died yet so you have some time to:

1. Read everything you can find in this forum about P0153. (Search this forum)
2. Buy/borrow a Haynes/Chiltons manual and read it.
3. Post back here with what you're about to do.
4. We can help, we just need more details.

Karl

Thanks Karl,

Sounds like good advice to me, and I should have thought to search before posting, enthusiastic newbie error I'm afraid.

I'll get back when I get to the next step.


Michael

PO 0153 - To quote the Ford manual is a
"HO2S Sensor Circuit Slow Response. See P0133 - The HEGO Monitor checks the HO2S Sensor frequency and amplitude. If during the testing the frequency and amplitude were to fall below the calibrated limit, the test will fail." That is what sets the code and a low system voltage might do that.

Ford lists the following areas to check: "Contaminated HO2S sensor; Exhaust leaks; Shorted / open wiring.; Improper fueling; MAF sensor; Deteriorating HO2S sensor and Inlet air leaks."

Know that this list was published based upon engineering and may or may not cover the reason the code was set. Experience is usually the best guide and you can find that some of that on this forum.

Based upon the statements of those who have some experience with these things, the failure of an HO2S sensor is NOT common but the MAP is a common concern.

Now I have a 2000 Windstar with 140,000 miles on it and it is just broken in good. There are no deposits or wear inside the engine. I have always used Penzoil 5w-30 as the manual calls for and serviced it on the regular use schedule. I have never used additives in the engine or other systems.

So, based upon what I have experienced with my vehicles and what I remember of the notes of the authors of this forum, I think that I might clean that MAF sensor. Low system voltage can give you strange happenings with codes and this is a test that did not ring true for the computer, so I would give my battery a load test, and check the alternator voltage for proper output voltage. An improper voltage could easily mess up the test that turns on DTC codes. If this happens only after letting the vehicle set for a few days then my very first checks would be a battery load test especially after setting for a few days and alternator output voltage check. If the battery is low after setting for a few days then load check it after a fresh charge and if that is okay then check for battery drain with the key off.

Good luck.

Jim

Thanks Jim,

I'll check that out. I think I can figure that out with Haynes, but if not I'll ask.

Interestingly, I've seen a dimming/brightening of lights at night, but only a few times. Lights got brighter with higher rpm's those times.

I just replaced the P/S pump, tensioner, drive belt- and the alternator seemed a bit noisy internally (brushes?) when turning the pulley by hand.

Sounds like that might be a part of it.

Regards,
Michael

Jim,

By the way, thanks for mentioning that your 2000 Windstar with 140,000 miles on it is going strong. It makes me feel good about the longevity of these vehicles with proper care.

In April, I got my 1998 Windstar GL with 137K, moving up from a 1986 Dodge Caravan SE which I've had for nine years (and that minivan's still running pretty good too).

Regards,
Michael

I thought I'd post what I'm figuring is a happy ending to this intermittent P0153 code I was getting.

After more than two months with no problems/no codes, I've decided that the problem was due to contaminated fuel, and NOT bad O2 sensors.

I bought my '98 Windstar that had been sitting idle for a while, with little fuel in the tank, and I immediately started getting code P153, but sometimes it would go away. Following wiswind's suggestion that I fill up the tank and throw in some Techron, there has been no problem since.

So, I'm learning that sometimes the simplest possible, often overlooked solution, might very well be the right one. My suggestion to all, is to make sure there's at least 1/4 or more of a tank of fuel in there at all times, and more is better, because who know's what's sitting in the bottom of the tank...

Thanks to all who helped with this one.

Michael