Topic: Newbie with check engine light (pulled 3 codes)

[gsst5888]

  Hey guys, I'm as green as they come on this forum and on mustangs. I just bought one last night, got a deal I couldn't pass up from my brother in law. I drove it straight to autozone and they pulled 3 codes.... PO171  PO174 and PO300. Only thing I know about it is BBK headers and full exaust with a cold air intake. I'm told the codes are bank1 lean, bank2 lean, and misfire code. This thing runs super strong but I want to fix it right. If anybody with experience on this could give me a starting point I would greatly appreciate it. (95 4.6 SOHC 5 speed) I was told it was a special order 5.8 but I found a 4.6 belt routing sticker on the hood so that must have just been some bad information somewhere down the line. Thanks in advance for the help. -Gary   

[Soaring]

 There is a mass airflow (MAF) sensor or manifold absolute pressure sensor at the intake, typically mounted either in the air tube feeding from the air filter box to the throttle body.  The mass airflow sensor does exactly what its name implies; it senses the mass of the air that flows past it, giving the computer an accurate idea of how much air is entering the engine.  If it gets dirty, it will send wrong information to the computer, therefore my suspicion is why it is running lean, and misfiring.  Too much air, not enough gas. The next component in line is the Throttle Body. The throttle body has a throttle position sensor mounted onto it, typically on the butterfly valve of the throttle body. The throttle position sensor (TPS) reports to the computer the position of the throttle butterfly valve, which the ECM uses to calculate the load upon the engine. Take the MAF out and clean it.  You will need to buy a special little tool to get the MAF out.  Then use an air intake system spray cleaner and a Q-Tip to clean it.  If that intake system has a K&N filter in it, those filters are sprayed with an oil that will get on the MAF.   If this doesn't fix the problem, then you will probably need to take the car into a Ford shop.  Here is where the MAF is located on my 03 Mach 1 with the 32 valve 4.6.

 

[gsst5888]

 I'll start with that, reset computer, and see what happens. It does have a K+N filter so it's definatly a possibillity it could be that simple. Thanks for responding, I'll let you know if it works. I really appreciate you taking all that time to help me out!    

[Soaring]

Not a problem.  Let us know if you have success. 

[gsst5888]

  Cleaned MAF sensor and reset computer yesterday after work, no more check engine light!!!!!!!!! Drove around for about a half hour and it never reset. Thank for the help soaring. I can't believe it was that simple. 

[Soaring]

I never have that kind of luck.  Usually a start on a project thinking I will be through in about an hour, and three days later I'm still working on it.   
Oh, on that K&N air filter, there is a special kit you need to buy at autozone or wherever.  The kit has the cleaning fluid as well as the oil in it.  Just take the filter out and spray the cleaning fluid on it inside and out and let it sit for 10 minutes, then use the spray nozzle on the hose and spray it down real good.  You will now notice it is pink again.....that means it's clean.  Now, spray a little oil on  the outside and put it back in the car.  Do that every time you change your oil.  And do change your own oil.  Use a quality synthetic oil and a motorcraft filter.  I use Mobil 1.  Royal Purple and Amsoil just cost too damn much, and test have proven them to not be much better than Mobil 1 that you can get at walmart. 

[gsst5888]

  I have several toys with K+N filters so I keep a pro charger kit stocked in the garage at all times. I'll freshen the mustangs up next weekend during oil change. I will get Mobile1 oil and I think I read in another thread that the motorcraft filter has a good anti-drainback valve so I'll pick one of those up also.

 You running 5w30 or 10w30? This GT I got didn't come with a manual.     

[Soaring]

It is written right on the cap.  Mine uses 5-20.  Sure sounds thin to me, but Ford has built a close ratio tolerance engine and that is the oil the engineers are saying to use, so who am I to argue?   

[gsst5888]

  I ran out and looked, my oil cap just says "engine oil". My brother-in-law said he changed the oil right after he got it in November, I'll ask him today what he put in it. I'll bet ya he just put in 10w30 since he probably wouldn't of known otherwise. That may also explain why it has a little topend chatter after you first start it cold for about 10 seconds.
   5w20 mobile1 and motorcraft filter on the way next weekend, I was also going to dump a quart of duralube in it but I think I'll wait and see if the fresh 5w20 will fix the slight chatter on cold starts first before I thicken up the viscosity with duralube.
    thanks again soaring.     

[Soaring]

Not a problem.  But, I think I would do some more research before I put 5W20 in it.  That is what my 03 Mach1 32 valve 4.6L uses, but I don't know about the 4.6 engines prior to 03, so don't take my word for it.  Yeah, the motorcraft and Wix filters are the biggest bang for your buck.  They both have the anti-drainback valve in them.  The chatter you hear when you start it up could very well be that there is a Fram filter on there.  Those cheap things are dangerous for engines.  All of the oil drains back in the oil pan to include the oil in the filter, so it takes the pump a few seconds to get oil to the lifters, but if it chatters for 10 minutes, then you may not have good oil pressure.  Try some new synthetic and I think you will be very pleased. I actually thought I had gained a few ponies when I changed to syn. in my 65 289.

[jethat]

in 2000 Ford changed to 5w-20 from 5w-30 mostly for fuel economy. They recomend all prior modulars use 5w-20, I dont think its a big deal either way. Not gonna hurt the engine if you put 20 or 30. I have ran both in my 5.4 truck. Just use good oil I use motor craft simi synthetic in my truck and the motorcraft filter other like wix napa gold amsoil K&n are also good. DONT USE FRAM. No anti drain back and some of the cheap oil in & outs use crap filters to.
I use fully synthetic in my car I only change the oil in it once a year. I only put 2 or 3 thousand miles a year on it though.

[Soaring]

I put 3 or 4 thousand miles on my mustangs, change the filter, add another quart, then drive another 3 or 4 thousand before changing the oil.  The K&N and Amsoil oil filters are great, but they cost nearly twice as much as a Wix or Motorcraft, and the quality difference is iffy.  Ford recommends you change the oil every 6 months whether you drive the car during that time or not.  That's because condensation happens, and we all know that oil and water don't mix.  I don't know how true that is, but I still won't go passed 6 months without changing the oil.  Old habit.   

[jhayjhay0918]

I guess that there's no anti drain back and some of the cheap oil in & outs use crap filters to.


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