Vacuum leak?
Where does it seem to be coming from? I know that's the $64 question.
Hey, if you update your profile with your vehicle details you won't have to type it every time.

 

Thanks - Thought I had the details in there.

When driving sounds like front driver side and it's a big whoosh not a small sucking sound - that said always hard to tell when moving and cant seem to tell when idle in front of hood although maybe behind rather than in front of block.

 

Could it be a plugged cat? Matches with where you hear it and loss of power.

 

How would I check that ?

 

Can you tell if its a slipping transmission.
Rpms go high power goes down.
Inspect transmission fluid for color and burnt smell.

^ X2. on the bad catalityc converter.

 

Can you tell if its a slipping transmission.
Rpms go high power goes down.
Inspect transmission fluid for color and burnt smell.

^ X2. on the bad catalityc converter.

Thanks for suggestion - I don't seem to be getting those symptoms - if anything revs are hindered and loss of power

 

I also have an engine light - codes are P0172 System Too RIch Bank 1 / P0170 Fuel Trim Bank 1. Replaced MAF and air filter - no change- same symptoms

 

Also light did not come until after I started experiencing the issue.
Additionally there is also a metallic rattled that starts after you let off the throttle and goes away after 5 or so seconds - none of these systems were present before the issue started.

 

1.If your exhaust gas smells like rotten eggs or sulfur.
2.Makes a funny noise, sorry I can only describe it using the Letters F and R(rolled as in Spanish language) for a more dramatic effect(lol) It's like fffffrrrrooom!
3.And if the CC is really clogged up both previous symptoms and the catalityc converter will be glowing red hot. This is an extreme case.
That bad smell is the 1st sign.

What part did you changed?
1st gens have no MAF AFAIK they use MAP sensors.
Running rich P0172 if not corrected in a reasonable time will eventually clogg up the catalityc converter.

Is the engine temperature reaching normal level at a reasonable time? If the thermostat is failed open the engine dumps lots of fuel to warm up the engine.

Any misfires? This = unburnt fuel = lots of carbon and soot.
Inspect exhaust manifold for any leaks.

Dirty fuel system like the injectors, fuel filter also create problems for the CC. All that fuel that is not atomized properly creates lots of carbon or soot residue which clogs up the CC.

 

1.If your exhaust gas smells like rotten eggs or sulfur.
2.Makes a funny noise, sorry I can only describe it using the Letters F and R(rolled as in Spanish language) for a more dramatic effect(lol) It's like fffffrrrrooom!
3.And if the CC is really clogged up both previous symptoms and the catalityc converter will be glowing red hot. This is an extreme case.
That bad smell is the 1st sign.

What part did you changed?
1st gens have no MAF AFAIK they use MAP sensors.
Running rich P0172 if not corrected in a reasonable time will eventually clogg up the catalityc converter.

Is the engine temperature reaching normal level at a reasonable time? If the thermostat is failed open the engine dumps lots of fuel to warm up the engine.

Any misfires? This = unburnt fuel = lots of carbon and soot.
Inspect exhaust manifold for any leaks.

Dirty fuel system like the injectors, fuel filter also create problems for the CC. All that fuel that is not atomized properly creates lots of carbon or soot residue which clogs up the CC.

Thanks for all this - yes MAP not MAF was changed https://www.amazon.com/gp/product/B07L9S82VP (thought the 2 terms were interchangeable)
Temp seems okay, will check for smell on exhaust - not real excited about running it too long to see if cat glows but it's sounding like that may be next test
I seen online you could run I think it was lacquer thinner through the gas tank that could help clear the cat without splitting the system - is that accurate / does it work / any concerns ?

 

I haven't tried the Laquer Thinner.
But im considering turning mine 180 deg.
I have another vehicle with V6 and the CCs began to smell. I have a welder so trying that is cheaper than replacement. Assuming they can be rotated 189 deg.

The only way I would use LT is with Catalityc converter removed from the vehicle and let it steep infor a while. If I had a parts cleaner station I would definitely run the LT through the Catalityc converter until solvent came out clean.


LT is a strong solvent it will be heavy on rubber hoses and plastics specially fuel pump internals.
I still insist if you decide any solvents like acetone or anything else. Remove the CC and try outside. These vehicles don't like even E85 under prolonged conditions. But acetone and Laquer Thinner are really harsh on everything they come in contact with.

 

There has to be something loose or failed. Cat may be the odds on favorite. I still think there may be something else. Check hoses, intake, ...

 

The running rich condition needs to be fixed first. If you install a new Catalityc converter and there is excessive fuel dumped th the CC it will go bad as well.

BTW
I don't plan on getting rid of the conectors. I'll cut about 1 to 2 inches away fron the connectors. Turn CC 180 degrees and weld it back.

 

If you step back a few feet that's how the vehicle sounds. I really don't know if it's a combination of backpressure escaping the front donut gasket or downpipe connection. Or may be from tailpipe from little gasses that can flow through.
But I'm sure if you stand behind the vehicle and rev it up you will hear it from the muffler area or the side.

But at the end if it sounds like that there is a chance it is clogged up or at least restricted.

There is a tool that is used in place of the front O2 sensor, it's a needle gauge, once in place with the engine running it will show either pressure if it's restricted or clogged up or vacuum if it's good.

The other alternative would be to disconnect the muffler. I've seen and heard the same noise from rusted internals of the muffler. Idk if this is the case but it's only 2 bolts or nuts can't remember.

It would nice if you had a test pipe or make one. Just a piece of tubing to by pass the CC just to get a feel for it. Unless you live far from the city and disconnect the CC AND GIVE IT A TEST DRIVE .

BTW that's not me yelling at you, that's how loud your V it's going to sound. Lol

 

If you step back a few feet that's how the vehicle sounds. I really don't know if it's a combination of backpressure escaping the front donut gasket or downpipe connection. Or may be from tailpipe from little gasses that can flow through.
But I'm sure if you stand behind the vehicle and rev it up you will hear it from the muffler area or the side.

But at the end if it sounds like that there is a chance it is clogged up or at least restricted.

There is a tool that is used in place of the front O2 sensor, it's a needle gauge, once in place with the engine running it will show either pressure if it's restricted or clogged up or vacuum if it's good.

The other alternative would be to disconnect the muffler. I've seen and heard the same noise from rusted internals of the muffler. Idk if this is the case but it's only 2 bolts or nuts can't remember.

It would nice if you had a test pipe or make one. Just a piece of tubing to by pass the CC just to get a feel for it. Unless you live far from the city and disconnect the CC AND GIVE IT A TEST DRIVE .

BTW that's not me yelling at you, that's how loud your V it's going to sound. Lol

Thanks - Does that cat look okay as a replacement if it is the cat or is it cheap junk ?

 

It depends where you are. Some states are now asking for certified catalityc converters$$$$$ just like California.

 

FL - everything goes No emissions check

 

Still wonder if your intake tube is leaking somewhere. Between air filter and intake. You may be leaking air in. Or such. Simple to check. Look very carefully.

 

Maybe try the old carburetor cleaner trick? Spray some cleaner in the area where you suspect an intake leak, if it gets taken up into the engine you'll notice the effect, usually a revving.

 

Just to close this thread out - it was the CAT - the replacement part was as listed earlier in the thread - approx 70 bucks US - pay attention to review comments as they are accurate, U will either need to drill out holes on down pipe a little, ruse old spring loaded bolts or buy new spring loaded bolts from Honda. I also had to get a CO2 sensor removal tool approx 15 bucks from Carmax as the access wasn't great for the tools I had - all in all with the job and getting tool was about 4 hours - thanks to everyone for their thoughts / troubleshooting / advice - never seen this issue before but you helped me get to the right outcome - see pics, front end input to cat was pretty bad (after 170K miles), should look similar to pic of the rear (with the 3 bolts) when new / clean ;-)