Honda Car Forum

My '00 HX (manual transmission) keeps getting two P1491 error codes but only under certain conditions. The engine has to be cooled down (stopped for 4 hours or more). The pair of codes only occur at the 2 1/2 to 3 mile point (I assume that's at the end of its warmup cycle). At that point the car's throttle response is not smooth (almost surges) and the codes register. It's fine after that. I stop the car and clear the codes and even though I have an 80-mile commute the next time they come back is when I go home for the day, and again at the 2 1/2 to 3 mile point after leaving work. Outside temperature seems to make no difference. I have the factory service manual and have tried the troubleshooting procedure several times but have yet to come up with a definitive answer. I have 2 EGR valves and the same thing happens with both.

Hey, I have a 99 HX MT - I usually get 42.5 mpg weekly tanks on 2 days city 5 days hwy driving in 60 to 75 F weather No A/C.

What mpg do you get?

I don't know about your tranny problem too, maybe a Honda Tech would know.

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I drive a 1999 Honda HX MT
1993 Mazda MX6 LS
1999 Dodge Grand Caravan Sport

The '00 has 302,000 miles on the odometer due to the daily commute I have (80 miles one way.....74 of those are on the interstate). I'm still on the original clutch, too. Nothing else has gone wrong on the car and the hybrids don't justify the extra cost for now.

Over time I've learned how to drive it for the max mileage. I periodically see how well it's running by checking its mileage. The farthest it's ever gone before the low fuel light came on was 741 miles.....that works out to about 50mpg because even though the owners manual says the tank holds 11.9 gal tank I can stuff 14+ in it by filling it up to overflowing. That's the only way I can know for sure how much it's actually used.