Hello everyone I have a Toyota Prius 2011 3rd gen around 155k miles that is throwing a misfire code on cylinder 3. I ran a can of the gumout (looks like the seafoam can) tuneup through the gas tank and the code disappeared for a month or so. I just got these plugs https://shop.advanceautoparts.com/p/denso-iridium-tt-spark-plug-ixeh20tt-4711/10713048-P?navigationPath=L1*14923%7CL2*15034 and am replacing them tonight weather permitting. I'm hoping I'm on the right track. Next thing is should there be anything else I need to look at while I'm in there? Say try testing the ignition coil? I've read where there have been fuel injector issues on these also. Any input is much appreciated!
2011 Gen 3 Prius Misfire
- Thread starter Rtstrider
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You might want to swap the coil on cylinder 3 when you are changing plugs. I.E. use #2 on #3 and #3 on #2.
If you get another misfire, but on #2 cylinder, then the coil is suspect. If it's on #3, then it's something still common to that cylinder, like the fuel injector, wiring to the coil (or similar) or some mechanical issue.
Since you will have all the coils out to swap the plugs, it is no more work to put the #3 coil in another cylinder in case it's not an issue with the plugs.
If you get another misfire, but on #2 cylinder, then the coil is suspect. If it's on #3, then it's something still common to that cylinder, like the fuel injector, wiring to the coil (or similar) or some mechanical issue.
Since you will have all the coils out to swap the plugs, it is no more work to put the #3 coil in another cylinder in case it's not an issue with the plugs.
On priuschat.com, I've read of several cases of misfire due to clogging of the EGR system, especially including EGR passages in the manifold, and the EGR cooler (heat exchanger). Typically such clogging occurs at around the mileage you report. As I understand, the manifold passages can be cleaned, but the heat exchanger is difficult to unclog.
My 2011 Prius has not had that problem yet, at a little under half the mileage you have.
My 2011 Prius has not had that problem yet, at a little under half the mileage you have.
Several years ago our 2001 Impala was showing a misfire code on one of the cylinders and sometimes running rough. The dealer said to try a can of Sea-Foam so I did that. The problem went away for six months and came back. I tried another can of Sea-Foam and the problem went away, but came back a little shorter than six months. I tried another can of Sea-Foam and the problem went away, and came back in even a shorter time. I started to think about what could be causing this. The car still had the original fuel filter on it, so I reasoned that it was possible that the fuel filter was pretty well clogged up and that the Sea-Foam was opening up enough passage for the fuel to flow fast enough again. So I changed the fuel filter and the problem never came back.
Plugs first, if there is still an issue then further diagnose. Don't get the horse before the cart.
Originally Posted By: Trav
Plugs first, if there is still an issue then further diagnose. Don't get the horse before the cart.
this.
Plugs first, if there is still an issue then further diagnose. Don't get the horse before the cart.
this.
Check the plugs if they are still original, but it is likely not your issue.
If you have access to a scan tool, command the EGR during light acceleration and see if the misfire can be duplicated. If it does, remove the manifold and replace it with the updated manifold as outlined by the service bulletin.
Also, as previously mentioned, the EGR pipe AND the valve are notorious for clogging up on these. They have a water-cooled EGR system. If the clog is bad enough, it can cause a misfire as well. Remove the EGR pipe and the EGR valve. Fully disassemble the EGR valve and clean it up well. The EGR valve can be removed w/o removing the EGR cooler if you remove one of the studs for the EGR cooler.
Some of these motors will develop headgasket leaks as well, but hopefully that is not your issue.
If you have access to a scan tool, command the EGR during light acceleration and see if the misfire can be duplicated. If it does, remove the manifold and replace it with the updated manifold as outlined by the service bulletin.
Also, as previously mentioned, the EGR pipe AND the valve are notorious for clogging up on these. They have a water-cooled EGR system. If the clog is bad enough, it can cause a misfire as well. Remove the EGR pipe and the EGR valve. Fully disassemble the EGR valve and clean it up well. The EGR valve can be removed w/o removing the EGR cooler if you remove one of the studs for the EGR cooler.
Some of these motors will develop headgasket leaks as well, but hopefully that is not your issue.
Or to summarize the EGR components I listed earlier and others The Critic did, the entire EGR system is suspect---pipe, cooler, valve, and manifold passages. Clogging of the manifold causes uneven distribution of EGR to the cylinders, which causes misfire.
Alright guys I didn't have time to get to the car this past weekend. I'm going to give it a go this coming up weekend (hopefully). These spark plugs are very skinny! I'll keep everyone posted
edit: No towing with the prius
edit: No towing with the prius
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Originally Posted By: Rtstrider
Alright guys I didn't have time to get to the car this past weekend. I'm going to give it a go this coming up weekend (hopefully). These spark plugs are very skinny! I'll keep everyone posted
edit: No towing with the prius
The spark plugs require a 14mm spark plug socket, not your usual 5/8". The windowshield wiper arms, cowl trim, wiper motor and cowl tray (lots of tiny bolts) will need to come out in order for you to access the plugs. Also, get the plugs from the dealer. They recently changed the spark plugs to a hotter temp range and none of the aftermarket catalogs (including Denso and NGK) reflect this yet.
Truthfully, your time is probably better spent on removing the EGR tube (4 nuts) and inspect that area before doing the plugs. If the EGR is plugged up, that is more likely to be your immediate problem.
Alright guys I didn't have time to get to the car this past weekend. I'm going to give it a go this coming up weekend (hopefully). These spark plugs are very skinny! I'll keep everyone posted
edit: No towing with the prius
The spark plugs require a 14mm spark plug socket, not your usual 5/8". The windowshield wiper arms, cowl trim, wiper motor and cowl tray (lots of tiny bolts) will need to come out in order for you to access the plugs. Also, get the plugs from the dealer. They recently changed the spark plugs to a hotter temp range and none of the aftermarket catalogs (including Denso and NGK) reflect this yet.
Truthfully, your time is probably better spent on removing the EGR tube (4 nuts) and inspect that area before doing the plugs. If the EGR is plugged up, that is more likely to be your immediate problem.
As far as troubleshooting, I generally do not like more than one change at a time. The above suggestions are valid, and swapping coils is a good idea, as is checking the EGR. However, it is always nice to know the actual reason for the issue, just in case it pops up again.
Alright changed the plugs and single cylinder 3 coil. The plug was ashed up and white. I pulled the egr tube cleaned it and the orifices it plugs into. The EGR system really wasn't too dirty. I also cleaned the throttle body which was basically spotless. We've driven about 20 miles and the code has come back. P0303. I'm thinking next step would be a fuel injector? Ideas?
Originally Posted By: Rtstrider
Alright changed the plugs and single cylinder 3 coil. The plug was ashed up and white. I pulled the egr tube cleaned it and the orifices it plugs into. The EGR system really wasn't too dirty. I also cleaned the throttle body which was basically spotless. We've driven about 20 miles and the code has come back. P0303. I'm thinking next step would be a fuel injector? Ideas?
Do you have access to a scanner? Follow the instructions on the bulletin and command the EGR system under the conditions described. See if the misfires appear during those conditions. If not, then we can revisit other options.
Alright changed the plugs and single cylinder 3 coil. The plug was ashed up and white. I pulled the egr tube cleaned it and the orifices it plugs into. The EGR system really wasn't too dirty. I also cleaned the throttle body which was basically spotless. We've driven about 20 miles and the code has come back. P0303. I'm thinking next step would be a fuel injector? Ideas?
Do you have access to a scanner? Follow the instructions on the bulletin and command the EGR system under the conditions described. See if the misfires appear during those conditions. If not, then we can revisit other options.
I broke down and took the car to the mechanic since it's outside the easy fix realm. They replaced the intake manifold Friday and told us to drive it this weekend to see if the car would relearn the proper air/fuel ratio. It got MUCH worse and was misfiring like crazy. Out of all the plugs I put in the cylinder 3 plug was black with carbon. p0303 is back and it's back in the shop being looked at. They said they're checking the head gasket today since the injector tested out good. They also put in a new plug in cylinder 3 and moved the new coil I installed to another cylinder. There's no coolant loss or oil/coolant mix that we can see. The oil dipstick was bone dry is what they said so I had them go ahead and change the oil.
Turns out I was right all along. This was an injector issue. The mechanic said they were able to clean the injector off the car. They just did the diy stuff you see on youtube with cleaner. Said there was some crud that came out of it. So far so good and no misfires for now. The injector is not on cylinder 1. So if it does misfire I'll be looking for a p0301 code. I have already started searching for a matched set of remanufactured injectors in the meantime. My fingers are crossed this is a permanent fix, but, if it's not then we at least have a backup plan
I am not one to claim that top tier gas is always the solution. However, after using el-cheapo gas in my Ecoboost truck and getting all sorts of weird misfires, I switched back to Chevron, used injector cleaner and the problem has not returned. 70,000 miles later, all is well.
The cheap gas was in fact, the problem.
The cheap gas was in fact, the problem.
Originally Posted By: Rtstrider
Turns out I was right all along. This was an injector issue. The mechanic said they were able to clean the injector off the car. They just did the diy stuff you see on youtube with cleaner. Said there was some crud that came out of it. So far so good and no misfires for now. The injector is not on cylinder 1. So if it does misfire I'll be looking for a p0301 code. I have already started searching for a matched set of remanufactured injectors in the meantime. My fingers are crossed this is a permanent fix, but, if it's not then we at least have a backup plan
That's interesting - Toyota failures tend to be pattern and injector failures are not common on that motor. I've seen clogged injectors on the older 1.8s (1zz-fe) but on the newer 1.8s, it's mostly oil consumption (bad rings), egr issues, intakes (sometimes) and headgaskets on the very high mileage ones. Glad to see that you were able to get it resolved.
Turns out I was right all along. This was an injector issue. The mechanic said they were able to clean the injector off the car. They just did the diy stuff you see on youtube with cleaner. Said there was some crud that came out of it. So far so good and no misfires for now. The injector is not on cylinder 1. So if it does misfire I'll be looking for a p0301 code. I have already started searching for a matched set of remanufactured injectors in the meantime. My fingers are crossed this is a permanent fix, but, if it's not then we at least have a backup plan
That's interesting - Toyota failures tend to be pattern and injector failures are not common on that motor. I've seen clogged injectors on the older 1.8s (1zz-fe) but on the newer 1.8s, it's mostly oil consumption (bad rings), egr issues, intakes (sometimes) and headgaskets on the very high mileage ones. Glad to see that you were able to get it resolved.
I installed the remanufactured injectors yesterday. I got these off ebay. $105 shipped with lifetime waranty. They are denso. The one injector that caused the misfire was visibly discolored on the end. So far so good with the new injectors but we are giving it a week or two to call it fixed. If this was indeed the issue then I will be shipping the old injectors off to trav for a cleaning in the next few months. That way we have spares on hand. The old injectors were definitely dirty. If the misfire is fixed I'll be running a bottle of redline through the fuel system to clean up any carbon crud left from the misfire. We will also be running top tier fuel to keep this from happening again.
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