First of all, fault codes never say to replace parts. They only indicate the circuit or system that needs further diagnosis. I don't have a listing for code 1113 to know exactly what is setting that one.
P1114 Engine Coolant Temperature (ECT) sensor circuit intermittent low voltage
The 1114 code is most commonly caused by a wiring problem and least likely the temperature sensor. Misfire codes don't tell you the reason for the misfires. Based on that lack of information, what sensors are you going to order? What will you do when they don't solve the problem?
Very few mechanics will install parts that customers provide. It's more common than you think to get new parts that are defective. Also, some aftermarket parts, particularly sensors, may work fine for one application but not in another due to subtle differences so you can create a new problem even though that part is listed for your car. The markup shops charge for parts, just like at any other store, covers the cost of ordering replacements when they're defective, the cost of delivering them, and the cost of re-diagnosing the system again later and replacing the new part if it caused a problem. When you provide the parts, it's like bringing your own food to a restaurant. If the steak is tough you'll still be expected to pay them for cooking it AND you'll be expected to pay for them to cook a second one. If your new parts are wrong or defective you will still owe the mechanic for installing them, and for installing the next part. He didn't do anything wrong if the part is bad and he should not be expected to work for free.
The story is different if you're going to do the repairs yourself. You can buy the parts from wherever you choose. Mail order stores can be a good value if you don't need any advice or help. Many auto parts stores will rent or borrow tools if you buy the parts from them. In some cases that can save you a lot of money on special tools you don't have to buy. The problem still is what are you going to do when the problem is still there? You'll have to go back to the mechanic who knows you cut his throat for a few dollars, and now you need his help again. How appreciative would you be in your line of work?
A better course of action, if you don't like the first estimate, is to get a second one from a different shop. Compare them to be sure they found the same diagnosis and recommend the same repairs.
Wednesday, March 20th, 2013 AT 6:26 PM