Engine ping on 2.2VTEC on 97 Accord

I have a 97 accord with 200K miles. For over 30K, I have been
experiencing engine ping at part throttle. Two mechanics haven't been
able to find anything wrong during general inspection periods.
I recently had a tune up and valve adjustment which didn't do anything.
I tried a bottle of techron in the gas tank, which also didn't help. If
I try a higher octane gas, the ping either improves and sometimes
dissapears, however I would rather not use premium gas. I tried all
kinds of brands of 87 gas, no difference. I installed a new radiator a
while ago and my coolant level is fine. Recently, my check engine light
came on. The fault code EGR Flow Insufficient P0401. I reset the
engine light and it hasn't come back in about 1K. I plan on taking my
car into my mechanic in the next few days. Could this fault cold have
anything to do with engine ping? Any other suggestions to help fix this
problem?
Thanks

 

Why don't you want to use premium? Because it costs more? Don't be so sure
until you have compared the cost of driving the same distance with regular
and premium. It may be that premium costs less or doesn't cost any more
than regular to drive the same number of miles.

Yes, probably everything to do with it. EGR will reduce the tendency for
an engine to ping as well as reduce NOX emmissions.

-jim

 

Low EGR flow will definitely cause ping under load. Your EGR system is
likely well carboned-up. Time to get that looked at and cleaned out.

You should not have to use premium gas. Your car was made for regular.

 

:iagree: Sounds like carbon build up! Ask your mechanic about doing a
piston soak. Also you might want to Google a product called seafoam.

 

Is it just me, or do others think that this answer is extremely obvious?
Pinging at light throttle is commonly caused by a hot intake manifold or
insufficient EGR. You'd think that two mechanics could solve it.

The flashing MIL and chugging idle in my 2005 HAH might finally be
solved - ignition coil #3 didn't work. This is another obvious one that
should have been solved before I started began the lemon law process.
They looked for ECU codes, drove around with diagnostic equipment,
verified mechanical tolerances, and tried over and over to reproduce the
blinking MIL. Never did they examine the totally obvious symptom of the
chugging idle. I would have diagnosed this myself but I was curious
just how bad Honda's techs were. Now I know that I need to sell this
car before something that's actually complicated breaks. I would have
gotten about $30K back through the lemon law if the last repair found
nothing wrong.

 

two obvious questions:
1. are they experienced honda mechanics?
2. did they check the real basic stuff like timing? if the timing belt
has been changed, that could be out.

yes. go to tegger.com and read up on how to clean the egr system. for
the future, running injector cleaner through the car ever few thousand
miles helps minimize carbon deposit buildup.

 

That's got nothing to do with it. The deposits in question are in the EGR
passages, well away from the combustion chamber. Your solutions involve
combustion chamber deposits.