Stephen Miranda

Hi everyone,

I have done an exhaustive search regarding this issue on these forums and elsewhere. 90% of the posts I come across that include this code are people that are dealing with both a p0175 and p0172 code. I only have a p0175 code, no others. I recently bought my truck and dealt with a misfire on cylinder 5. Replaced all of the coils and spark plugs, used motorcraft spark plugs to make sure I didn't have any issues. The misfire went away, but I immediately got the p0175 code. Suspected that the issue could be a dirty or clogged fuel injector, since this truck seems to have had almost no maintenance done other than oil changes. (Trans fluid and spark plugs were original when I changed both last week)

I ran fuel injector cleaner through the engine using Chevron premium gas and also cleared the code with my OBD reader. The code went away for a few days. The battery has seen better days so i decided to get a new one. As soon as I replaced it, I got the p0175 code within 20 minutes of driving. I have a very simple OBD reader but took a look at the freeze frame data and it indeed looks like I have a rich condition as my long term fuel trim on bank 2 is (-27%). I have cleared the code twice since changing the battery, it has come back both times. I am now debating just leaving it on and seeing if the computer just needs to adjust to get the fuel trim mixture right.

Currently the truck exhibits no symptoms of this code. There are no misfires, no black smoke coming out of the exhaust, I have not felt any loss of power. The truck idles at around 800rpm and feels smooth. The truck does have a muffler delete, I don't know if that would affect the code coming up or not. I am now looking for where I should focus my efforts. I have replaced the air filter, but have yet to clean out the MAF sensor. Though I am not sure if it would have anything to do with either of those, considering this issue is only on bank 2.

One thing that may or may not affect this, my positive battery cable terminal was very corroded. I cleaned a lot of the corrosion away at the connection, but there is still some corrosion on the outside. I know that a leaky fuel injector may be the issue here as well, could it be likely that the misfire I previously experienced on cylinder 5 was caused by a leaky fuel injector, and that may be why replacing the coils and plugs did not solve everything? From what I have read, it is not likely to be a fuel pressure issue since anything related to that should affect both sides correct?

I have also read that it could be an issue with an oxygen sensor, but if it was that, wouldn't that mean that my freeze frame data would not have shown an actual rich condition? Basically I'm trying to figure out the likely culprits based on the fact that I only have a p0175 and not a p0172. I have read that the symptom being on one bank narrows down the causes, but I have not been able to figure out exactly which causes it narrows them down to.

I have included screenshots of my freeze frame data below.

https://imgur.com/a/6DMCIP1

Any help is much appreciated. I will be checking this frequently and will try to respond quickly. I know how helpful these posts can be to future user so I want to try to be as responsive as possible. Thanks everyone.

Jbrew

I believe limits go to 25% before exceeded. Well, check this Scorpio page out, they are accurate with this gen of 150 as far as troubleshooting, -

http://www.fordscorpio.co.uk/fuelmonitor.htm

Stephen Miranda

Thank you for sending me this, from reading the beginning it looks like it has some very useful information. Considering the max it will deviate from the correct fuel trim is 25%, does that mean my OBD monitor might be giving me wrong info?

cjd777

Check the PCV valve connection behind the TB, mine split and was almost melted. Autozone sales a replacement kit for both ends for about $7.
I didn't say it was going to be easy to get it off and the new one on.