What Would You Do?


Keeping in mind that I am not a mechanic and can’t make these repairs myself, I’d like to know what y’all would recommend in this instance.

I posted yesterday about my 2001 Hyundai Santa Fe which has a check engine light coming on, is lurching while in drive, and requiring gas pedal to the floor to pull out of a dead stop at times, but not all the time. Two folks suggested it might be the fuel pump or fuel filter.

Anyway, today I took it to Advanced Auto Parts and had them hook it up to their computer (someone on here had recommended that auto parts stores would do that for free in another thread, so thanks whoever you are!). Two codes came back: P1529 - Mfr. Control Vehicle Speed Idle Speed Control input and P0175 - Input Turbine Speed Sensor A Circuit Malfunction.

The guy at the parts store recommended a shop to take it to and I went there. As soon as the owner saw the codes, he said, “Oh, let me guess, a Kia.” Well, Kias and Hyundais are the same thing, so I felt pretty good that he has some idea of what he’s doing. He said that he had just replaced the same part on a Kia the week before. He told me could get the parts on Monday and I’d have my car back Tuesday morning. The estimate was $350.

So, out of guilt, I took the car to the shop where I used to take my Ford Escort back 8 to 10 years ago before I got my Santa Fe. The owner is a great guy, but when I showed him the codes, he scoffed and said, “They’re just trying to sell you something. Let me hook it to my machine on Monday. I won’t charge you to look at it. It’s probably just a loose air hose or something.”

I feel disloyal not going to Nick, the guy I used to go to. The only reason I never took my Hyundai to him was that it was under warranty until a year ago. Anyway, should I go to the guy who sounds like he knows what he’s doing, but I don’t know.

Or to the guy I know and have trusted before now, but who inexplicably doesn’t trust codes generated by other machines than his own.

For what it’s worth, I went to a third shop just because I’d like to have a price to compare it to, and the third guy wanted $70 to hook it to his machine, also refusing to accept codes not from his own device.

Oh yeah. I should also divulge that my husband neither likes nor trusts Nick, the guy I used to go to. But I think he’s very nice and honest.


Postpone your decision by going to Nick Monday morning. He will probably determine that it is not “a loose air hose or something” and that the Kia/Hyundai guy is correct. Then ask him for a better deal. I don’t know how hard or easy it is to make the necessary repair, but both shops ought to be able to handle it equally.

BTW, no shop should accept codes from anywhere else. It is correct for a mechanic to always do his own diagnosis from scratch.


Can I ask a really dumb question? Okay… I just did, but now another one. Why shouldn’t someone accept a code from another shop (assuming the customer is being honest and not making stuff up)? Aren’t the diagnostic machines all the same? I’m not being facetious; I sincerely am curious. I only went and got them because someone on here had suggested it to someone else and I thought it would streamline the process. I have two small boys that I have to take everywhere with me so time is always of the essence when I’m in a business. Thanks for your help, btw.


I agree with Steve, no reputable mechanic would proceed without reading his own codes.

Frankly, I see nothing in the post to suggest that any of the parties has been less than honest and competent. Since you’ve trusted Nick for a long time, and he seems understanding of your situation, I’d suggest continuing with him. It’s always been my belief that an honest capable shop deserves the customer’s loyalty. Having said that, I realize that I’m not the one who has to go home to your husband, so I really couldn’t fault you for going to the new guy either.

Nobody in this scenerio has done anything wrong or dishonest that I can detect. The choice is yours.


If a mechanic accepts the codes from another shop, he then becomes liable if the problem isn’t corrected. Codes are only a clue telling the mechanic where to head, they’re not perfect. That doesn’t mean that he totally disregards the information, anybody any good takes in all the information offered and digests it all together. If he reads slightly different codes he’ll take all the information together. Any good tech will take his own codes.

The suggestions to get the free code readings are usually made to those doing their own work or those who want some basic idea of what to expect when they go to the shop.


“Why shouldn’t someone accept a code from another shop (assuming the customer is being honest and not making stuff up)?”

How would you expect to get an accurate diagnosis from another mechanic without him doing his own reading?

Since you went for a second (and third) opinion - a very good idea - you need to let them do their job. A second or third reading of the same code would at the very least confirm that the original reading was accurate. Or a second or third reading could give completely different results.

A mechanic, doctor, computer tech or anyone who diagnoses problems needs to evaluate the situation on his/her own in order to make an evaluation worth consideration. The other mechanic could have a faulty machine, made up the code or any number of possiblities.

Any mechanic (or doctor etc ) who acts on someone else’s diagnosis might do work that isn’t needed.

Then who do you blame?

The person who gave the reading to the mechanic?

Or the mechanic who didn’t check to see whether the work done was really needed?


Only part of the diagnosis is the code. The code doesn’t explain exactly what is wrong, so experience and a good mental diagnosis ability is t as or more important than the code. Both mechanics are using their experience to predit (before they hook up the machine) an outcome. There is nothing wrong with that. As mountainbike points out below, good mechanics will at least verify the codes on the spot. They won’t repair until they are fairly certain of the problem. This diagnosis requires re-looking the codes and verifying what they are. The person at Advance Auto is merely a sales person helping you out, and not a real mechanic. Good mechanics trusts their instincts and their experiences, along interpreting the results of the various diagnostic tools they have. That is why a good mechanic is worth his weight in gold. As SteveF indicated, give Nick a shot and see what his conclusion is, after he does a real diagnosis. There is no reason to disbelieve either one at this point. Hopefully Nick is right and the answer is a cheap one. If not, as an independent, maybe he can come in with a less expensive cost.

I hope that explains your question without seeming circular or confusing.


Let Nick go over your car Monday; if he comes up with the same readings, great. Now, some trusty old mechanics have not kept their skills up to date, and may not know what to do with the readings! If Nick comes to the same conclusion, and suggests simlar repairs let him do it.

I have been burnd several times in the past by “trusty old mechanics” who were not familiar with such things as computers and fuel injection systems.

Good luck and keep us posted!


Can y’all tell I’m a horrible decision maker? Thanks for all your explanations. They do make sense. I just hate dealing with stuff like this. When I was growing up, my mom worked on her own car. Her dad had taught her how. And if she couldn’t fix it, then my cousin who was a mechanic would take a look at it.

I wish life were that simple for me.

Anyway, thanks so much. I guess I’ll be taking the car in to Nick’s shop Monday morning and crossing my fingers.


A true horrible decision maker never would have asked the questions.

And we all hate dealing with stuff like this. Even me.

Sincere best.


All day long we make recomendations based upon info,codes given to us by other mechanics,we are limited,we are a internet forum.All mechanics want to do the diagnostic process from start to finish on their own.It’s part of the training.Giving good auto repair advice when you cant see,hear,smell,test drive,verify is a challenge.