2000 Taurus SES - repeating trouble codes - vacuum leak maybe?

I'm new to this so I apologize if I accidentally break any posting rules.

I've had a few codes show up multiple times. I took my car in because at the time I didn't have time to do the work myself, so I had a mechanic look at it. They patched me up and said it's fixed, then the codes came back. I know the shop is scamming me because I've taken it to them on more than one occasion so I'm going to do repairs myself from now on since I have the time. The codes I've been getting are:

P1506 - IAC overspeed error
P0352 - defective coil #2
P0430 - low catalyst in bank 2

The IAC I've replaced no more than 2 months ago. I've replaced all ignition coil packs and spark plugs. I've replaced both oxygen sensors and replaced the rear catalytic converter. The only thing I can think of is a vacuum leak somewhere. Highly unlikely everything I've replaced was defective.

I'm thinking maybe the PCV is cracked. I haven't checked that yet but I'm getting on that in the morning after the car is cooled down. I don't know how to check for vacuum leaks in the engine. I was told to use something called B-12 gas to highight where the hole is.

I'm convinced it's a vacuum leak because even when idling I'm at about 1500-1700 rpm sometimes just sitting still. I need to get this fixed before it does something to my transmission. I've been told a faulty fuel pump could cause similar problems but not sure how to check that. It could be working, just not strong enough to send the proper amount of fuel or maybe the fuel filter is clogged from dirty gas.

Anyone have any ideas or suggestions?

Is anyone willing to offer advice on this problem?

My parents have a 03 Taurus and were having the same issue with codes coming back even after the work was done they were cleared. Finally I told my Dad to take the car to the dealership and have them run a full diagnostic. If turned out that the computer was retaining the codes and had to have a full reset. After the dealership reset the codes (around $60.00) the codes are gone and have not come back. Worth a try, sometimes.

Your codes are pretty widespread, so it's difficult just by the codes to suggest where to start looking, but a routine tune, including inspecting for vacuum leaks is a good start. That should at least get you a baseline.

You'll need a fuel pressure guage with the Ford adapter (most come with this) to check the fuel rail fuel pressure.

I think it's interesting that the shop is being accused of scamming you, yet you have not been able to solve the issue either. Obviously it's not a simple fix. If the shop held on to every customer's car for a week and put 100 miles or so on the odometer just to be sure every car they see is fixed, plus charging the customer for their labor to do so, they'd be accused of scamming as well plus have no repeat business since they kept the car so long. It's a delicate balance, and they probably really did feel the car was repaired. What did the repair order say they worked on?

-Rod

Your codes are pretty widespread, so it's difficult just by the codes to suggest where to start looking, but a routine tune, including inspecting for vacuum leaks is a good start. That should at least get you a baseline.

You'll need a fuel pressure guage with the Ford adapter (most come with this) to check the fuel rail fuel pressure.

I think it's interesting that the shop is being accused of scamming you, yet you have not been able to solve the issue either. Obviously it's not a simple fix. If the shop held on to every customer's car for a week and put 100 miles or so on the odometer just to be sure every car they see is fixed, plus charging the customer for their labor to do so, they'd be accused of scamming as well plus have no repeat business since they kept the car so long. It's a delicate balance, and they probably really did feel the car was repaired. What did the repair order say they worked on?

-Rod

I do routine tune ups every 10,000 miles or so. The reason I say I was scammed by the garage is because they say they fixed all trouble codes including the bad coil pack. I told them to find the cause of the IAC and MAF codes and they said they found it. A week after I got it out of the shop, the codes were back. This was the fourth time I'd taken it to the shop to have this taken care of.

Further inspection showed they used the wrong model coil for my engine and had the wires bared somehow and they were arcing causing it to malfunction. Also during a brake replacement and suspension check I found a hose not connecting to something but haven't found where it goes to yet. I didn't remove this hose when doing repairs and have found no evidence it broke off from somewhere else. I will not be going back to that shop again.

The only codes left are the for IAC and MAF, both of which would be caused by a vacuum leak. The filter is clean, all connections are where they should be. Both components are clean and working normally, yet the codes are still there. Everything seems to be right yet the codes are still there. I read somewhere in this situation it'd be wise to check the PCV. Due to the heat of the engine and just wear and tear it's likely to crack. Some of the original components I haven't gotten around to replacing yet so I wouldn't be surprised.

I will be checking for a vacuum leak and find where that hose is supposed to go. Perhaps it's the cause of it all. I will keep everyone posted.

If you could take some photos of that hose and post them here, someone may recognize where it goes. You'll want to include a pic showing its relative location as well (not just a close up that only shows the end of the hose). Also, there should be a vacuum diagram under the open hood of the car that shows where the various vacuum lines go.

-Rod

If you could take some photos of that hose and post them here, someone may recognize where it goes. You'll want to include a pic showing its relative location as well (not just a close up that only shows the end of the hose). Also, there should be a vacuum diagram under the open hood of the car that shows where the various vacuum lines go.

-Rod

When I find the problem, I'll be sure to post pictures of what's going on and how I fixed it. I checked this forum's sticky for the lean codes and it lines up with the IAC problem as well as posts on other forums. From what I've read it's just a vacuum leak. Mine's a 2000 with 125,000 miles on it so that would make sense that it's wear and tear on the seals, gromits and PCV. I'll keep everyone posted.