Can a timing belt change cause Honda Odyssey 2005 EXL Malfunction Indicator and no more ECO?

Just purchased a used 2005 Honda Odyssey EXL with 81,xxx miles on it. The timing belt had never been changed and had been used in a very cold climate. We went ahead and changed it, and water pump at the same time. Today, less than a month after replacing the belt, the malfunction indicator lamp is on. In the manual I have read that this means one of the engine’s emissions control systems may have a problem. It says continued operation may cause serious damage. It also says the malfunction indicator may be due to a loose or missing fuel cap. I triple clicked the fuel cap on as suggested. It says it could take three days for the indicator light to go off, if this was the problem. I also have noticed that the variable cylinder operator light does not come after the timing belt was changed. Are these warning lights linked to the work done on the timing belt? Thank you for your input.

No they are not linked to the timing belt, I dont think the two are related at all ! However if you bring your car to a autozone or such store they will scan your computer and tell you what the car says is wrong with it.

While it may not be linked to the timing belt, it’s possible that something got knocked around and broken while they were under there.

One idea. Your rear engine mount may be shot and sending a code. These have a sensor of some kind that makes them dampen the engine vibration when ECO is down to 3 cylinders. A symptom is a growl in ECO at lower speeds and the cause is the parts of the mount loose their cushion and it results in metal to metal contact. I had to replace mine but I don’t recall any malfunction code so this may be irrelevant to your problem.

Basically we need the exact code that caused the check light. It could be just any out of range sensor, without details… We all are geussing.

Unlikely to be a direct result of the timing belt change, but the variable cyl light never lighting up after the timing belt change could be caused by a connector that they had to loosen to change the timing belt, and forgot to put back on. That wouldn’t be unusual.

tighten the gas cap and the problem may well go away by itself in a few days.

If not, you’ll have to do as suggested above, then post the code here for the pro’s here (of which I am not) to decode for you.