Does anyone know the symptoms of a catalytic converter going bad?

Mine seems to be running pretty good, but my milage has dropped 10 to 15 mpg. This is disturbing. I just had the 90,000 mile service done and the technician said that it's not throwing out any trouble codes. The IMA also seems to be discharging and charging quite often. When the battery is fully charged, it will drop down to half charged just going up an onramp on the freeway.

This is frustrating me.

Howard

I don't think that's the CAT. Mine's blown twice and it didn't affect FE. It just made the "check engine" light come on and made the exhaust stink.

There are some other things you might want to check:

-- Front end alignment. If the wheels don't point the same direction, it's going to really suck down gas and drag down the IMA charge (I know this firsthand too).

-- Tune-up: That 105,000 tune-up... You might want to get it done a little early. I did mine at 90k and it helped out quite a bit.

Chris

Thanks Chris. I have the front end checked. It seems to be tracking fine. I'm thinking, maybe it could be an accumulation of a number of things. I just put on some new Michelins, had the front brakes redone and of course the main culprit, I think, is the A/C. IT'S BEEN FLIPPIN' HOT and the A/C has been on alot.


Howard

Yup... Blasting the AC will certainly lower your gas mileage AND make the IMA run down faster. Oh well... What can ya do?

My check engine light has been going on and off for the past month. Initially, the dealer said it was just the gas cap not being tightened down enough. When it continued intermittently for the fourth week they finally decided to check it out. It was infact my Cat. It will be replaced under warranty as I have 81,000 km on the car. The mileage has been so up and down the past month as well. I thought it was just my daughter drivering it that caused the poor F.E.

Lovely... The catalytic converter just blew again. I had it raplaced only 9 months ago. Fortunately, it seems that Honda also believes that a $2600 part should last longer than 12,000 miles. I should hear back around Wednesday if Honda will fix it for free again. It seems like they will.

I went through this with my Honda Insight (See my website below, Horrible millage, 3 cats in under 100,000 miles)

Go to a PRIVATE shop and have them do a manual test of the 02 sensors. Honda apparently doesnt know how to do this.

I read your website. What a terrible experience you've had! I don't blame you for being mad as hell.

At least the fuel economy and battery array has been okay in my car.

The 'check engine' light mysteriously cleared without actually having any work done on the car. Has the CAT suddenly come back to life?

other news: I only now, at 108k miles, had to replace the brake pads. That's a really long time!

Dealer diagnosis: my 2003 HCH needs a new catalytic converter because 'the only code it's throwing is for that'. I'm at 85,000 miles and have had a very intermittent malfunction indicator for the past three months or so.

Question: Is the catalytic converter different because it's a hybrid? The online parts catalogs seem to show that it's the same as for a 1.7l Civic.

I'm headed to a private, highly-recommended Honda place for a second opinion. I'll ask them to do a manual check of the O2 sensor.

My car doesn't seem to be affected by a recall, although I'm getting a strong sense that catalytic converters are a problem...