Rep Power: 0

2008 Civic Hybrid 1.3L 290000 miles

Code P1861

Just had spark plugs replaced

Was noticing the car was starting to lose power at highway speed while going up long hills.
I took the car into a local mechanic and they replaced the spark plugs.
This helped the issue and I was able to continue commuting to work and even a longer trip to go back home over the holidays.
After getting back from the long trip the issue started to get worse but I was still able to drive the car carefully being mindful of rpms.
Fast forward a couple weeks, the issue has gotten so bad that putting the engine over 2600-3000 rpm make the the car lose engine power/acceleration.
The car can't even get past 20 mph in some cases now.

Thinking it could possibly be a dirty solenoid from or weak coil packs from a test I used from ( pulling plug out slowly while engine is running ) 2 out of the 4 showed no change at all.
The car is due for a new battery and oil change.

Trying to figure out if I should just call this one a wrap or if I'm close to finding the fix

Would love some insight!

 
Rep Power: 367

remove plugs and check the color. If coils not working, color should show it

https://www.google.com/search?q=plug...jphSe3oqHnO5uM

 
Rep Power: 0

The spark plugs didn't seem to have much different of a color when we pulled them to check. Maybe a little black

 
Rep Power: 222

Cat plugged?

 
Rep Power: 0

I initially thought this, is there a way of telling?

 
Rep Power: 0

How can you tell if the cat is plugged? This was on my list of culprits initially. There's 2 Cats one closer to the engine then another one shortly after. Which would most likely get plugged?

 
Rep Power: 0

I'll give it another look and get back to you

 
Rep Power: 222

Loosen the exhaust flange before the cat and see if acceleration improves

 
Rep Power: 0

I'll do this and tell you the results!

 
Rep Power: 0

I loosened the o2 sensor on the 1st cat and this seems to have solved the issue. Should I hollow out the first or second cat?

 
Rep Power: 0

I completely removed the O2 sensor on the 1st cat and the loss of power at 2500 RPM is no longer happening. This is leading me to believe that one of the cats are plugged.
Any ideas on which cat would most likely be plugged?
Should I try to use a cat-con cleaner? Should I remove the cat and soak in a degreaser?
Most likely going to try disconnecting the exhaust between the 1st and 2nd cat to break up and remove the clog. If that proves too difficult I might resort to drilling the cats to break them up.
Any recommendations would be greatly appreciated

--- Original Post ---

2008 Civic Hybrid 1.3L 290000 miles

Code P1861

Just had spark plugs replaced

Was noticing the car was starting to lose power at highway speed while going up long hills.
I took the car into a local mechanic and they replaced the spark plugs.
This helped the issue and I was able to continue commuting to work and even a longer trip to go back home over the holidays.
After getting back from the long trip the issue started to get worse but I was still able to drive the car carefully being mindful of rpms.
Fast forward a couple weeks, the issue has gotten so bad that putting the engine over 2600-3000 rpm make the the car lose engine power/acceleration.
The car can't even get past 20 mph in some cases now.

Thinking it could possibly be a dirty solenoid from or weak coil packs from a test I used from
( pulling plug out slowly while engine is running ) 2 out of the 4 showed no change at all.
The car is due for a new battery and oil change.

Trying to figure out if I should just call this one a wrap or if I'm close to finding the fix

Would love some insight!

 
Rep Power: 222

You replace the cats, otherwise Captain Planet gets angry

 
Rep Power: 0

If Captain Planet has an extra $700 I would be more than willing haha
I feel bad about it but at least the car has a tiny engine/ hybrid
All jokes aside you have any tips?

 
Rep Power: 222

I would assume that the primary cat would clog first, check with an exhaust shop, might be able to weld in a new cat cheaper

 
Rep Power: 367

put o2 sensor back, remove cat 2 (will sound like a truck, but should answer the question 1 or 2. (If both are bad, you are going to have to change both)

 
Rep Power: 367

if you decide to hollow, do the 2nd. 1st one could trigger the o2 sensors
Have at least one cat working. Do you have smog tests where you live?

 
Rep Power: 0

Sounds good, I will do the second one first.
Will it damage the engine if I end up having to clear out both and drive it around?
I don't have an issue if there's a constant engine light from the o2 sensor
I live in a rural area so there's no smog tests

 
Rep Power: 367

having the light on means you will not know when another problem comes up

Cheaper comes expensive later on

 
Rep Power: 0

Good point. I only need this car to last me 6 more months and it has such high mileage that I just need it to work temporarily until I can afford a new car.

 
Rep Power: 222

Just make it a habit to scan the car every week/month

 
Rep Power: 0

Thanks everyone! I will update when I've made more progress in the next couple days. Should be warm enough to get it done!

 
Rep Power: 224

Removing one or both cats will likely make the exhaust tone change as well. May be louder and sound more raspy.

 
Rep Power: 367

PS:
There is a reason cat are being stolen from cars...[no, I don't condone this practice]

If you sell to a recycler, you could maybe partially pay to weld pipes in its place (2nd cat is the one that you can do this easily, the 1st have the sensors) - [no, I don't condone doing this either - but considering COVID situation...]

 
Rep Power: 222

Yeah with it being a hybrid, you should get pretty decent money for the cats rather than zero for hollowing then out