maf or o2
 

Hello everyone! quick question. I just bought a 97 f150 5.4l truck. the lady i bought it from said it needed an o2 sensor. When i got it home, I did a scan for codes. it came up with p0171, p0174, p0153, p0401, p0307, p0301 and p0302. When I look theses up it all suggests a dirty or malfuncting MAF sensor. So my question is. Would a faulty o2 sssensor come up with its own code?

Moved to Correct section :thumbsup:

When banks 1 & 2 codes are set together suspect the MAF or fuel pressure. Aka P0171 & 174. I would start by pickin up some CRC MAF cleaner and try cleanin it first. Disconnect the negative battery cable when you do this. Another way to test it, is while the truck is idling tap on the MAF sensor with the handle of a screw driver. If idle changes its bad. As far as P0301, P0302, and P0307 are concerned those are all misfires they have nothing to do with a MAF sensor. Depending when and if the plugs were ever changed, and with it being a '97 I'd go ahead and replace the plugs and wires. The other 2 codes should be 02 related, which could be caused by the misfires you're having. Give it a good tune up and clean the MAF and you should be good to go. You may end up having to replace the O2 sensors, but that's maintenance.

I know I have a 4.2 BUT. was getting those codes.i know the plenum in the 5.4 don't have problems. But I did find when took the upper intake off 4 of 6 egr ports were clogged shut also read where that will make the truck throw lean codes too. So just an idea. I know it's ALOT of work to get to em to clean em but if all else fails may wanna try it. That's my experience.

Since you are getting the 171 and 174 codes, I doubt it is a oxy sensor because both would not be likely to go at the same time. The 3 codes indicate a misfire at plug 1, 2, and 7 so you might have loose plugs or need new plugs or have bad connections at the plug wires. The 401 code suggests a stuck EGR valve or a plugged up EGR tube. You can clean the EGR valve and run a wire through the pipe from the valve to the manifold to make sure it is free of obstructions.
Don't get solvent on the EGR diaphragm or you will have to buy a new EGR.

Cleaning the MAF is always good maintenance and I would also change the air filter. I also recommend cleaning the plug sockets before you install new plugs by using a round wire brush (like a plumbers or 12 gauge brush), WD 40 and rags wrapped around the brush. Also fix any oil leaks at the valve covers or PCV valve that would cause oil to leak in the plug socket holes.

That 153 code is indicating bad oxy sensors but, as noted previously, it seems doubtfully to me that both would go bad at the same time. I would fix your other problems first and see if the codes clear. The 153 could just be a bad wire connection at the plug. In any case, it will be easier to identify if all your other issues are fixed.