pumafeet10

Looking for some insight into a couple issues i have been having, but first a little background...

I have a 97 HX with the D16Y5 with 172k on it. I have owned the car since November of last year, and have had no problems to speak of.

Lately i have noticed that there is a small amount of black soot on my rear bumper, where the exhaust cut out is obviously.

meaning there is unburnt fuel making its way through the exhaust, very bad in my book

Also while driving in 4th gear at or below 1500 rpms and at ~ 80% load on the engine i have a slight hesitation or power drop, feeling as if i was closing the throttle, and then back on then off again.

My thoughts are TPS and O2 sensors, but unsure if i could really test to see if they are functioning properly.

I do get very good gas mileage over 550 my last tank BUT i do hypermile the car and with my last 00 civic hatch, i was doing better then that with less hypermiling practice, so not sure what to do

I have not replaced anything on the car since i purchased it except fluids, plugs,cap,rotor, and ignition wires.

Any help would be greatly appreciated as i am trying to use as little fuel as possible and keep my car running in tip top shape

Former User

Any CEL codes?

Is the ignition timing set to spec?

Have you cleaned out the EGR valve and its ports and passage ways in the intake manifold?

pumafeet10

I have not had any codes, but i was just remembering when I had the car inspected back in december i was driving to the acura dealer where my brother in law works and going up a long semi steep grade with about 80% load as per my scangaugeII i had a random misfire and a cel that was blinking and a few codes came out, which at the time i was thinking it was just dumping fuel, that was the description of one of the codes and it went away when i cleared the code.

I am not sure if the ignition timing is correct or not, i don't have a timing light, but i can read timing whilst driving but haven't had a chance.

I did forget to say aswell that i had a wierd feeling about the egr and the track on the intake mani, but was thinking about removing the injectors sending them to RC having the cleaned, balanced, and flowed that while doing that i could check the EGR and clean all of its associated hardware

I have thought that my catalytic converter might not be functioning properly either as the car has 172K and the heat shield on the cat is only being hold on by one of the bolts.

Former User

What were the codes that were thrown?

I'd start by cleaning the EGR valve and the EGR chamber ports and passage ways in the IM. My guess would be that they are clogged up with carbon.

pumafeet10

i guess i should look into the process it will take to remove the egr valve and chamber, hopefully it is as simple as it looks

Project Dad

what is hypermiling

Former User

A driving style that maximizes gas mileage.

pumafeet10

so today while driving the car started to hesitate in 3 rd gear and not 4th! not sure what is going on, as i can't work on the car atm with the rain

so frustrating, also is there proper way to clean the egr system? I haven't looked if anyone has documented it, just thought i would ask

pumafeet10

also today i used my scangauge to read the ignition timing while driving was at 7-9 degrees, does that sound right?

99ssinoc

My money is on 02 sensor... rock auto ftw.

pumafeet10

I have a feeling that is part of the problem as well, but am actually afraid to take out the first o2 sensor because of the sad shape the manifold and cat seem to be in, and i can't afford a new mani/cat right now

99ssinoc

If I'm not mistaken I think that is the main objective of the 02 is to tell the ecu/engine when to add or remove air:fuel mix. When I had my VX I held the throttle at 80% at any rpm (manual) and when it was held steady; I had the bog. When WOT it ran great and if I feathered it; ran great. Idle was fine. Check into an 02 sensor, you would be surprised at how resilient those parts you named are, even rusted. Make sure you get an 02 puller tho =p

pumafeet10

oh im sure my mani and cat will be fine problem is me wanting to buy new ones! haha

I really want to just over haul the whole car right now but cash flow is on the low, so hoping i can do this piece meal and get 65+mpg this spring and summer while being WAY more effcient

Thanks for the vote of confidence hopefully i don't find a messed up cat or something haha

Kista20

I have both a 97 and 99 hx's and they are great cars but they have those little gremlins that pop up from time to time.

Some known issues that I have experienced are:

bad ecu - 97 & 99
bad 5 wire o2 sensor - 97
clogged egr ports - 97 & 99
cyl misfire - 97 & 99

also the cat is part of the exhaust manifold and is prone to cracking which is not a cheap fix. I haven't had any issues with that but a lot of people have.

honda had a bad batch of computers in the hx's but it's too bad that you are past the 10yr 150k warranty. All the work done on the 97 was fixed under that warranty and I never had to pay anything.

I'm sure the ecu had went bad at some point in the 99 because it has a cali spec one installed, it seems to run fine but I wonder if I could get better mileage out of it by finding a federal one. For the 99-00 there is an old spec ecu and a new one and I have the old spec but cali. I'm thinking it went bad and that's all they could find to replace it with since they are hard to find as it is. I bought the car used so I can only speculate as to why it has the wrong ecu in there and it was bought new and registered in va the whole time.

The egr system can be problematic but imo if you keep it cleaned every 90k-100k you should be good to go. It's not too hard just time consuming which make it a bit of a pain to do.

The 5 wire o2 sensor likes to take a dump anywhere from 100k-150k miles. I have yet to replace the 4 wire secondary one.

pumafeet10

hopefully i can get it sorted out a bit this week as the weather should be a lot nicer, and my soon to be brother in law went on the honda certified technician site and my symptoms were that of a clogged egr so hopefully that is all it is, for now

Kista20

You'll def. want to get those gaskets, in the picture that RonJ posted it says "gaskets replace" and is pointing to two of them... one is the egr chamber gasket and the other is the intake manifold gasket. I hope you won't need the egr valve because it sure isn't too cheap...

17146-P2J-004 - chamber gasket
18715-PB2-000 - egr valve gasket
17105-P2J-014 - intake manifold gasket

hx_man

28-30 mpg mixed
I had been wondering if i should just bite the bullet and try changing my o2 sensor. I should also try the thermostat but I doubt it is either one of them...
I have no codes ...
I wish some of you who had poor mpg on an hx would share your thoughts..

pumafeet10

Back from the dead... I have cleaned the egr system on the intake manifold, i didnt remove the intake manifold but removed any and all carbon i could.

The hesitation and misfire has been more pronounced lately, p0304,p0301,p1300,p1399
Have been the codes i am getting

I pulled the plugs today to see if anything looked off and went to the grocery store and was coming home and it threw those codes and had been missing pretty bad

Still stumped

pumafeet10

any more help?

grumblemarc

iTrader: (4)

??? No solution in 2 years?

pumafeet10

no, sadly. most of the time it has been non existent but recently it has come back with a vengeance

misfiring quite badly, i keep wondering if i should do an engine swap, buy a new car ugh

Whydid

Thinking about selling it? Where is it?

pumafeet10

Well i would sell it but not sure i can yet

hx_man

I'm not a mechanic, but (as a previous owner of a CR-V) I do know that the valves of these engines need to be adjusted every 100k or so. Have you ever done a valve adjustment? Ever checked the compression? If I were you, I'd get this done anyway to avoid the risk of the valves burning out.

I've also read that the O2 sensor (2 of them) can make these cars run poorly and throw misfire codes. These can be expensive but you might be able to find some at u-pull it junk yards.

Good luck!

BTW, I also had cleaned out the EGR valve and chamber but my HX still gets sub-par gas mileage. My mpg is around 30-31 city and 34-35 hwy. I've had better luck with 711, 87octane gas.

ej7attack

i swear i am having the same problems,the same codes everything. black soot on the rear bumper. does your car burn, consume oil. my car takes 2 quarts every 8 hours driving! to and from work and every week it needs 2 quarts. by now im sure that cat is half plugged up with carbon,soot. unburnt fuel is caused by missfire. missfire is caused by many reasons. so far ive went through the pcv system. replaced some components and still doing it. anyway im getting the same problems but waiting untill this motor is out of my car to inspect it because i suspect in my instance worn piston rings, or valve seals..just curious anyone, if the egr system was malfunctioning,wouldnt that trip a cel? i know it did in my 98 accord, which i cleaned the ports and was fine afterward.