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Engine Swap and near immediate Cam Position Sensor Replacement

I had an engine swap recently done on a 2005 Honda Civic, and within a couple days, Check Engine light came on. Mechanic ran the error code and I have to apparently replace the camshaft position sensor. They are claiming that the sensor was not replaced in the engine swap, and so not covered by any warranty.

Any information about whether this is valid would be great.

It would be useful to know exactly what the error code was, as well as whether engine sensors were expected to be changed in the engine swap. I am not familiar with the sensor and the placement of it on your Civic, but on my car this is a $45 part that can be changed in a few minutes.

Often, an “engine swap” entails using many of the parts from your original engine, such as sensors, manifolds, etc.

So the sensor was removed from the prior engine and installed into the new engine? I guess that is possible. Depends on how the cam sensor works in that engine. I concur w/oblivion, it shouldn’t cost too much to replace in any event. Also about posting the actual DTC numeric. I think the more concerning issue is whether there is actually anything wrong with the cam sensor. Just b/c there’s a cam sensor error code, that doesn’t necessarily imply the cam sensor is faulty. There’s other possibilities, including possibly the need to re-program the ECM to address incompatibilities due to the swap. But replacing the sensor may be the quickest method to finding out what is wrong, in the event it isn’t actually the sensor.

Was it an exact swap, the exact same 2005 engine for a 2005 engine? Or was something a little different? Is this a factory rebuilt engine, rebuilt by Honda?

If this was a used engine that was installed, you can run into that problem.


Appreciate all of the help. Mechanic is suggesting it is a $400+ repair ($80 parts/ 330+ in labor), because of the location of the sensor. It seems really expensive, but I know little about this.

The estimate states:

REPORT: Diagnostic Trouble Code PO340 ( camshaft position sensor malfunction )
stored. Tested output of cam sensor, no output, needs replacement.

REPAIR: Remove engine accessory belts and timing cover. Remove and replace the cam
posistion sensor. Clear fault code. Road test to run monitors to verify repair.

I was curious about all of this because it seems frustrating that after shelling out money to fix an engine, days later a sensor goes bad, and the cost to replace is extraordinary.

Its incredibly frustrating because despite there being a warranty on the engine, there is no way to prove that the sensor they used was originally mine, or replaced in the swap. I am not sure if that is something that is common, and I guess frankly I have to go based on their word.

In regards to George’s questions, as far as I know, it was an exact d17 2005 engine replacement. It wasn’t a factory rebuilt engine, or even performed by a dealer.

I feel like it is just horrific luck, but figured I would check regardless.

Again, I appreciate your help. I trust these guys, but unfortunately, when things are this expensive, I tend to double check everything.

Stranger things have happened. Hopefully it is just the sensor.

I think if I were in this position I’d want to first verify by visual inspection the cam shafts are actually turning. I assume they are since the engine seems to still be running, but if it won’t start now, definitely make sure the camshafts and the distributor (if your car uses one) are turning. And I’d want to make sure the camshaft sensor wiring had been inspected and tested for shorts as much as is possible, from the ECM to wherever it goes.

Am I missing something? They’re saying they spent about three hours to put the old sensor into the “new” engine? Was this a “short block” engine by chance?


Engine replacement has already happened. Two days after picking the car up, apparently the sensor went bad. This is what they are telling me now, and how many hours it would take to replace the sensor.

What about the timing belt, tensioners, water pump etc. I would not install a used engine without new timing components, especially when labor is so easy with the replacement engine out of the car. The shop should have mentioned replacement; Did they ?

Was your original engine replaced with a salvage yard used engine or a new or rebuilt engine supplied by Honda? What happened to the original engine?