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"Fuel Injection Service" vs. A Bottle of Techron.... is it worth it?

My mechanic… who I trust, is reputable, and has a 5 star rating from the mechanics files here at Car Talk, wants to do this “Fuel Injection Service” on my 2007 Suzuki SX4 (currently, 182k miles). I think they said it would run about 100 bucks. Maybe a little more.

I got a 6 pack of Techron from Costco, and put one in about once a month, or once every other month. Whenever I remember.

Is this high-priced “fuel injection service” worth it? They claim it will really clean out the whole entire system, and may even make the Catalytic Converter run better (I keep having one of the O2 sensors go off on me… the one behind the CC. They claim that if I spend another $400 to have the O2 sensor replaced AND do this “fuel injection service,” it might help with the CC too).

So… basic question. Am I really gonna get $100 bucks worth out of doing this? Or would a bottle of Techron do just about the same thing for a LOT less money?

Oh yeah, also… they say the plugs are shot. Another $100+ bucks (and yeah, I know it sounds like they’re trying to “make a boat payment” on me, but… FWIW… I have put almost 40k miles on the car since I bought it…)

It’s a revenue generator. Unless there are operating problems, I recommend against it.

If the “service” cleans out the fuel metering system, the only place the removed residue can go is through the cat converter. And IMHO it’s unlikely to make it all the way through. The theory is that a cleaner system makes the engine run cleaner and therefore deliver less unmentionables to the cat converter, but I always wonder if the stuff cleaned out of the fuel system (if there is any) deposits on the coating in the converter, reducing it’s efficiency.

Truth is, with today’s detergent fuels and clean engine operation, I believe that unless there’s a specific operating problem the engine stays pretty clean all by itself. As a matter of fact the problem being discovered with direct injection is that the fuel doesn’t wash the valves and that allows carbon buildup. Port injection allows the fuel to constantly wash the valves. Constant washing by modern detergent fuels has IMHO proven its ability to keep the engine clean.

Thanks. Your response is kind of what I figured… even though I like these guys and they get 5 star ratings.

I’ve kept constant track of my fuel economy ever since I bought the car. If the mileage was taking a steep nose dive, I’d notice it.

Don’t know if the Suzuki has direct injection or port injection… but your comments on that were certainly educational!

Way overkill. For 3 cars and many years I throw a bottle of Techron in once a year.
I once let it go for about 2.5 years to see if even that was a waste of money, and the idle got a little rough.
A bottle of Techron smoothed it out within 10 miles. BTW I use the cheapest gas I can find.
I’ve also used Techron to fix a chainsaw that was running poorly.
I also clean the throttle body at ~100,000 miles.

A complete fuel system service includes cleaning the induction system (manifold, ports and valves), fuel tank additives don’t do this. If you are a full throttle driver you may notice an improvement in performance but for most customers fuel system cleaning and gas tank additives make no difference in the driving experience. It is doubtful if this will cure your failing catalytic converter.

The plugs could be shot and need replacement how old are they?

On a car with this many miles, and the price of $100 for the clean and $100 for plugs, just do it. Likely this is the type of injector clean is the type where solvent is run through the engine while the fuel pump is disabled. $100 may seem like a lot of money but I’ve heard of shops charging $400 for the injector cleaning service. And it MAY just help your catalytic convertor. If you’ve gone 40K on the plugs, its a pretty good bet they need replacing.

Overall, both services for $200 is pretty small fee for maintaining a 185K mile orphan car. IMHO, most cars don’t wear out, we kill them by withholding maintenance.

That sounds like really good advice, actually. Even though I’d rather spend the $100 bucks elsewhere, that still sounds like pretty sage advice…

And yes… the plugs are shot. Mechanic told me they need replacing, and I have had the car for 40k miles and change now…

You might want to check with your mechanic on which brand of fuel injection system cleaner he is using. The best results I have experienced is from BG Products . They have a 3 part system that cleans the fuel injectors and induction system. The first is the fuel injector cleaner connected directly to the injectors with the fuel pump disabled. The second is connected to the throttle body and cleans the induction side. The third is the fuel tank additive which in my experience is the best on the market. I have used this brand for many years. I performed this cleaning on a friends 1993 jeep straight 6 cylinder 4.0 He told me he noticed an improvement that lead to cleaner smog test results and a better running engine. These products are only sold thru automotive shops. I also agree with the others, to change the sparks plugs.