Honda Element low idle 800rpm

So I have a 2007 Honda Element that has 300,000mi. I have been chasing a low idle ghost for about a year. I have replaced so many parts you might go…wtf? The body is good and interior is good plus it’s a reliable vehicle one of the best if not the best from what I understand . The milage can show that.
You prob know already where I’m going. Repeat O2 sensor code even after replacement. The code is the heater failure one. I have replaced the vacuum lines looking for air leak. Nope. I replaced the throttle body and gasket and tried to program with ecellerator. Nope. Plugs and coil packs. Nope. All the air box sensor and pcv valve. Nope.
Really starting to believe it either the the computer or the wiring to the O2 heater? I do understand that it might be the lean, rich, kill the sensor cycle but it doesn’t smoke or leave unreasonable soot.
It does not leak anything, overheat, or use oil. It throws only 2 codes the O2 heater and the evap canister. Can anybody give me a direction or advice. Thanks so much guys!

Run a compression test. With 300k on it both the rings and valves may a bit out of spec.


I’d thought about that. Honda reccomends a valve adjustment at I think somewhere around 150,000 mi ? Is their anyway for a bloke like me to do the compression test in my garage? Specific tool? Thanks mustang man!

[quote=“1defman, post:3, topic:180519”]
Specific tool?

It sounds like to me if you have to ask that question you need to find a good independent shop.


You should have had 2 or 3 valve adjustments so far.

Compression testing is easy. The tool can be borrowed from AutoZone and similar tool rental programs from parts places. YouTube videos and google searches can teach you how to do it and iterpret the results


Thanks bud appreciate it.

Won’t learn anything that way…sorry I’m new to fixing engines. Thanks for your…hmm…
help? Don’t you ever ask questions?


Eight hundred sounds about right. Question. Is the idle smooth or is it rough or slightly rough?

Best way to check for a vacuum leak is with a vacuum gauge as a leak may be somewhere not visible or even related to a hose.

I meant no offense as I had no idea if you was trying to fix it your self or just get ideas to tell a shop what was wrong.

Yes I ask questions all the time as I try to learn something new everyday again no offense meant as I don’t know your set up or what you are capable of doing.

How To Perform a Compression Test - EricTheCarGuy - YouTube


A oxygen sensor heater circuit failure is an electrical problem. The oxygen sensor heater needs power, ground and a complete circuit (no broken wires).
What is the fault code number?

All good. Context is hard and I usually catch crap cause I’m a newbie to these groups. I have been fixing my own car as since Honda told me to junk it 100,000 miles ago and refused to give me the code list I paid for. “We stopped at 26”…
And then still charged me. $800 for a ball joint, tie rod, and the code throw. Honda of Colraine OH. I apologize for be a smart ass sir.

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Hey no problem just don’t use any of the bad words or you may get flagged.

P0135 heater circuit bank 1. It’s the upstream I believe.

You need to test for power and ground to the oxygen sensor heater, check for damaged connectors and wiring. This is not cause by vacuum leaks or low compression.

Thanks Man. It seems like this is the way to go. I have always been suspicious of this code and my inability to get it to go away. But hey I’m down to 2 codes instead of 26… take that Honda of Colraine…

My wife did run it down in a shallow ditch and tore the passenger abs wires out. If I follow the course backward it makes sense she might have got the O2 sensor wire as well. Maybe above where it clips in for the sensor?

From what I’m seeing the correct idle rpm for an 07 Element w/2.4L engine is 700 - 720 rpm. So what you have at 800 rpm is not too low, but instead too high. How are you determining the engine rpm, some sort of meter you have? Is it accurate enough to differentiate b/t 800 and 700? If not, you idle rpm may already be correct.

BTW, this engine requires an idle re-learn procedure be performed after certain repairs, e.g. replacing the throttle body. Has that been done? This may require a Honda scan tool. Best done that way. You might be able to do it yourself by disconnecting the battery, shorting the two battery wires together overnight (to reset all the computers), reconnecting the battery, turn everything unneeded off, ignition on, wait 2 seconds, start engine, hold engine rpm at 3000 (in driveway, not on the road) until radiator fan turns on, then release pedal & let engine idle for 5 minutes.

The p0135 says there’s a problem in the heater circuit. In theory it’s a very simple circuit at the sensor.

B+ -------- heater element ---- ground

The problem is likely one of these

  • no B+ (12 volts) at the sensor
  • the heater element has failed (it should have a low resistance, but more than a dead short, should be appx 2-3 ohms.
  • The ground isn’t connected, or doesn’t have a low resistance, to chassis ground

Suggest before worrying about the idle rpm to eliminate what’s causing the O2 sensor problem, and the evap system problem. Either of those could make it impossible to get a smooth idle at the correct rpm.

Congrats on getting 300 k miles. You must be doing something right!! :slight_smile:


Again, +1

Rather than an idle speed that is too low, I suspect that the OP has a “lumpy” idle, which could easily be the result of a cracked vacuum hose on a 14 year old vehicle.