Hikari_NOS

Hi everyone, thought I'd throw out some of the problems that I've been having from my 01' V6 3.8L Mustang and see if anyone might have any ideas/insight as to what might be happening and what I can do.

Okay so to start out, I was having an issue with egr and fuel cap codes being displayed so I replaced all the parts(egr, dpfe sensor, and the solenoid) except for one sensor that connected to the charcoal canister, both of which are missing still, then replaced a few hoses connecting to the egr system that were worn. None of this ever caused any major changes in driving. The code went away after changing all those parts and having the system cleaned out, but only for about a month or so before I finally started getting another code for the system. This time it was P0401 which is "EGR Insufficient flow", so I thought that it may have still been related to the charcoal canister and the sensor that connects to it. Once again I ignored the code.

Car was fine for a few more months, then I started to notice that it was stuttering at lower speeds when accelerating. After the stuttering started, I checked the codes again, and this time I noticed that the P0171 code(system too lean bank 1) was being put out as well as the P0401. I was told that it could just be an misread code since it sometimes does happen with the o2 sensors, so I erased all of the codes from my car to see if it would happen again.

After another couple of months, stuttering continued but only a lot worse than before and the P0171 code did not appear anymore, just the P0401 code kept appearing a few miles after clearing the codes from the computer. Its been 6 months since I last cleared the codes that included the P0171, and just in the last week I've gotten the code P0174(system too lean bank 2). Now it seems that if I drive under 50mph the car has a very noticeable jerking to it but only when I accelerate, and anything under 25mph makes the whole car shake as if there is a small earthquake or something and RPMs will start to jump to about 2-4 thousand.

The last few months, I've also noticed what may be my transmission slipping out of gear. If I start to get up to speed, say 65-70mph from zero, to get onto the interstate, sometimes it will not switch and jerk really hard before finally switching into gear and accelerating properly. Then other times when I let off the gas after high speeds of about 60-70mph, the car's RPMs raise to about 3-5 thousand and it starts to slow down really quickly without me pressing on the brakes or using my e-brake.

The car is a V6 3.8L coupe with a K&N air filter (cold air intake), and has about 146,000 miles on it. Nothing else has been modified as far as I know since I bought the car used about 5 years ago. I can try to upload photos of the engine bay if anyone wants me to do so. I've changed the spark plugs, spark plug wires, egr, dpfe sensor, and egr solenoid, transmission fluid and filter, fuel filter, oil and oil filter, and have recently even tried cleaning out my air filter and re-oiling it, all in the last few weeks, but nothing has helped. The only other thing I can think of is a whole tranmission rebuild. Problem is that I don't want to spend all that money to have it rebuilt and then find out it was something completely unrelated that was causing all my headache.

If anyone has any ideas or suggestions then please let me know as it would be greatly appreciated. And does anyone know how much it is to have a transmission for a stang rebuilt or at least a general idea? Just in case I do have to have the transmission rebuilt. Thanks in advance for any help given.

Hikari_NOS

I take it that no one else has any suggestions? Anyone think my problem might be my MAF sensor? I've been researching and its looking likely, but I just want to make sure.

jthorn9

Maf sensor will cause a multitude of oddball problems ranging from running rich, to running lean, and everything in between. I wouldn't rule out the MAF but at this point you REALLY need to take the car to a mechanic and let them run a $100 diagnostic on the car and by that I don't mean pulling codes and scratching their heads, they need to run an electrical test on all the sensors to make sure they are functioning. My bet would be the MAF or a failed gasket or mechanical failure.

As far as the transmission goes 150,000 isn't a lot per say but depending on the type of lie the car had a rebuild may be needed soon especially if it's slipping.

Hikari_NOS

Gotcha. I'm gonna try to clean the MAF sensor this weekend and see if it helps any. Also planning on taking it in for an electrical test anyways since it has been making the chiming noise as if the door is still open occasionally and for some odd reason my back light on my instrument cluster for the gas gauge, specifically the full and 3/4th full section, starts to illuminate as if I've turned my headlights on, but the rest of the gas section other than those two areas stays off.

When you say failed gasket or mechanical failure, are you referring to the MAF sensor or the transmission itself? And what do you mean by "the type of the lie the car had"? Sorry if I'm asking so much, I would understand a lot more of this if I had already gotten my ASE certification. I'm currently working towards trying to get myself a job and go to college to get it, so I'm not yet fully car savvy. I know a bit about changing pretty much all the fluids/filters, and brakes, but when it starts getting too technical then I'm left questioning things. lol

Any idea or estimate of how much it'd cost to rebuild one? I've heard prices ranging from $500-$3,000. Thanks for your reply.

jthorn9

I meant life the car had.

The mechanical failure could be anything from worn parts in the transmission to the engine.

By gasket failure I mean that while unlikely, it is possible a gasket has blown on the engine causing the problem, my bet would be an intake gasket or a head gasket on the vacuum side which means its causing a vacuum leak.

Vacuum leaks will cause some really odd ball and headache inducing problems becasue while most are easy to find, some can be a real pain because the leak can be extremely minor but just enough to through the engine out of wack.

Hikari_NOS

Gotcha. Thanks I'll keep that in mind when I take it in to be looked at. When I got the car, it was quite obvious that it wasn't really taken care of, but ever since I've had the car, I've been maintaining it as best as I can and even trying to upgrade it with better parts to make it run better.

Thanks for your info. I really appreciate it. n_n

robb15033

How is the car? The lean codes and egr work needing done indicates a fairly large vacuum leak. That was something I was looking at, and clearing it, to wait & see if it comes back recently. A new pcv valve and a Seafoam treatment wouldn't hurt anything, good chance it improves a bit. Good luck, update when you can-

mustangmike09

What ignition parts did you put in and did you check the gap on the plugs ?

robb15033

I can give you some good proactive maintenance tasks that will most likely get the tips of your fingers on it, or somewhere near the issue here at hand, and delete it completely so you can get back in and drive that beast w/smiles everywhere.

The vacuum lines are grouped together horizontally across the drivers side firewall inside engine bay. They are some flexibility to them at that stage of the game. The vacuum lines that are bundled together near or above the engine itsself get hot, and the tubing gets hot and then starts to get hard & brittle, The group of three vacuum lines wrapped together within the twisted shielding are multicolored and crack or crumble easily. Sometimes broken up, crumbles while still wrapped with the shielding plastic. Anyways, one of the 3 tubes stems over and under the upper intake manifold plugging in below the TB housing. The other two lines head off in different directions. Just remember how easily they can be broken and unseen. Replace the plastic lines with small rubber lines when you can. You can spray that area and listen for change in idle rpm's. After vacuum lines are fixed and a new pcv valve is installed, Lets get this over with- I will swear by it_********
2 Cans of Seafoam. Pour one full can down int 1/2 to full tank of gas. Use second can to clean out upper intake and internal combustion parts. EASY~Put drinking straw into Seafoam can. Start the car. Pull pcv valve out and put the tip of the straw up to the PCV valve thats sucking air. Little by little till it's all gone. Drive away for 2 miles or so to burn off gas, Good To Go!! DO IT!

Hikari_NOS

Sorry about the delay replying back to all of your comments, been busy trying to get a job. Money is really tight right now. Anyways, I've already had most of the stuff involving the egr system replaced, the only couple of things that haven't been replaced or at least cleaned would be the O2 sensors and the MAF sensor (which me and my husband actually looked at and it was still pretty clean).

Definitely will try the seafoam again, haven't done that in the past year. As for how it's doing right now, not much better. Actually think it's getting worse. I've been keeping the fluids changed regularly, but it appears that the jerking is more than likely caused by my transmission. My husband's dad actually worked with a Ford dealership as a mechanic, and he told me that it definitely sounds like my lower gears are just worn out and the thing needs to be rebuilt.

@mustangmike09
Not sure what you mean by what I've put in for ignition parts. And as far as checking the gaps for the spark plugs, I generally just buy the already preset plugs and put them in after putting the anti-seize on correctly. I've always used the same spark plugs and never had any problems from them, so I'm fairly confident that those are fine.

@thread
And about those vacuum lines, yeah I've already replaced those too. I did that when I was replacing every other part of the egr system. Replaced them with the rubber hoses. Okay well I just looked up the pcv valve and that is one part I've yet to replace. *hits head on desk* Anyways, I'll actually buy that part too when we get some extra cash to see if that helps with some issues.

I'll try to keep thread updated as I go, but at the current moment, really need a job so I'll be checking back in when I can and answering back. Thanks for the help so far guys. n_n