Spark plugs

Hi all,

I live in Baltimore, MD, and I recently had to take my 1991 Honda Accord DX
to a mechanic because the car did not pass the NOx emissions test. I had the
emission mechanic do a fuel system service and replace the catalytic
converter, and the car passed the test.

Now, the emission mechanic also recommended that the spark plugs be
replaced. According to this emission mechanic, the current spark plugs in my
car are American made, and these plugs are not compatible with the Asian
vehicle. He claimed that this incompatibility is causing higher temperatures
inside the engine. I refused to replace the spark plugs because they were
installed 8 months ago (when I lived in IN) by a trusted mechanic. I wonder
if I did the right thing. Should I take the advice of the emission mechanic
seriously? Will the current spark plugs cuase any damage to the engine?

Thank you very much for any advice.

Fijoy

 

That emission mechanic was right. For your Honda, it's NGK! It's not
about the brand names or American vs Jap. It's the plugs heat range
ratings that are different from one manufacturer to another. If you
want to use Bosch or Autolite or Champion plugs, make sure you use a
good cross reference chart. But why would you bother with that?

As for heat range, if you don't know the correct heat range specified
for your engine, it's advised to err on the safe side. That is, to use
colder plugs. Hotter plugs can cause severe engine damages. And just
for kicks, try google ""hotter plugs" NOx"

That trusted mechanic in IN was a complete moron..

 

If the plugs are causing "higher temperatures inside the engine", it would
have to do with the heat range of the plugs, not the plugs themselves. It
is possible the non-OEM plugs are the wrong heat range and that there is no
correct heat range available in that brand.

No damage is likely with the existing plugs, but there have been many
reports of non-OEM plugs causing poor driveability.

If the car is running fine and has acceptable emissions results, leave the
old plugs in for now and replace them with the correct NGK or ND at the
next specified change interval.

If the car is exhibiting driveability problems and there are no other
obvious culprits, replace the plugs with the correct NGK or ND right now.

 

The NGK spark plugs on my car cost almost twice as much at the local dealer
than other stores. I wonder if they come with something extra at the dealer.

 

Sure they do. It's called a markup.

The only reason I buy any parts from the dealer is because I am therefore
certain of their quality. For parts like spark plugs -- where I can buy the
known-to-be-identical same thing from a jobber -- there is no point in
paying the dealer markup.

 

Spark plug seems to be the only thing. Other items seem resonable.

 

And batteries. And tires.

 

The cat replacement must have cost a grip! In relativity, your 91 deserves
the proper plugs. Only NGk and Denso will be recommended 'round here.

 

Batteries are slightly higher than the premium ones sold at regular stores,
but can't tell if they are the same quality and durability. I probably won't
buy tires from dealers as they only have limited selection.

 

Thanks for all your replies.

Fijoy