Rough Idle, Check Engine Light
- Thread starter joeflem
- Start date
T4R_Finally
New member
I have two toyotas and a dodge and Bosch doesn't have a good rep for any of them. If the plugs are new, I would replace the wires and coils and go from there. A flashing cel means stop and do not pass go so at least slow down until it stops flashing. I bought a code reader at advance auto on sale for $100. Pulls codes, clears codes, and can collect and then download real time data (never used that function). It has been handy for multiple vehicles and I imagine it would be especially useful in a state where you can't get it done for you.
habanero
Senior Member
BrianSD_42
New member
False.
This is completely false. There is no California LAW against reading a code at an auto parts store. Pep Boys will read codes for free, in fact I just had a code read about 4 months ago at the Pep Boys store near Genesee Ave in San Diego.
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If you are going to use the Torque app on Android be sure to pay the $5 for the full version. It is wayyyy better than the free one.
This is completely false. There is no California LAW against reading a code at an auto parts store. Pep Boys will read codes for free, in fact I just had a code read about 4 months ago at the Pep Boys store near Genesee Ave in San Diego.
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If you are going to use the Torque app on Android be sure to pay the $5 for the full version. It is wayyyy better than the free one.
Codes
No it is true. Pep Boys isn't just a parts store they are also licensed as a garage/mechanic so they can read codes for you.
No it is true. Pep Boys isn't just a parts store they are also licensed as a garage/mechanic so they can read codes for you.
T4R_Finally
New member
Takes a real mechanic to plug in a box that only fits one plug and then turn a key on, press a button and read some numbers. Some sort of union protection? Ridiculous!
BrianSD_42
New member
So you are saying that a shop must have a certain kind of license to read codes. Perhaps I am wrong because I know AutoZone won't do it anymore but I assumed it was just a CORP policy.
I know Pep Boys does it for free and you are right they are a full auto repair shop as well as parts store.
BTW, you can buy a Blutooth OBD-II scanner for about $30 on Amazon and the Torque app for $5. It work great.
Toronto_T4R
New member
same deal here
I've been having the EXACT same problem with my 99 SR5. Right down to the flashing CEL at high speeds. The problem is intermittent, but the only difference is that my CEL stays lit after the sputtering/low performance until it eventually resets itself. I bought the bluetooth code reader a few months ago and paired with torque it has proven to be excellent bang for my buck. I got a code saying that my Bank 2 O2 sensor was toast. I finally got around to replacing it on Saturday and have not had a problem since... fingers crossed. I can say however that the truck was running downright terribly when I bought it a year ago even after I seafoamed, cleaned, new air filter, plugs and wires.. but when I replaced the O2 sensor in the engine bay (bank 1?) the dang truck ran 200% better. It was unbelievable. I'm hoping switching out this bank 2 O2 sensor will solve the problem this time around as well. Please let us know if you solve the problem!
I've been having the EXACT same problem with my 99 SR5. Right down to the flashing CEL at high speeds. The problem is intermittent, but the only difference is that my CEL stays lit after the sputtering/low performance until it eventually resets itself. I bought the bluetooth code reader a few months ago and paired with torque it has proven to be excellent bang for my buck. I got a code saying that my Bank 2 O2 sensor was toast. I finally got around to replacing it on Saturday and have not had a problem since... fingers crossed. I can say however that the truck was running downright terribly when I bought it a year ago even after I seafoamed, cleaned, new air filter, plugs and wires.. but when I replaced the O2 sensor in the engine bay (bank 1?) the dang truck ran 200% better. It was unbelievable. I'm hoping switching out this bank 2 O2 sensor will solve the problem this time around as well. Please let us know if you solve the problem!
mikebontoft
New member
Let's not dance around the problem and throw parts at it. I am disappointed in that shop that said "needs new coils they're old."
I'd be happy to break it down into a good parts diagnosis when I get home. It's about two hour trip and I need to leave now.
By the way... the reason they don't allow codes to be read by parts stores? Some group of jackasses whined about their shops losing money on their "diagnostic fees" due to parts places offering free scans... so someone took action.
I'd be happy to break it down into a good parts diagnosis when I get home. It's about two hour trip and I need to leave now.
By the way... the reason they don't allow codes to be read by parts stores? Some group of jackasses whined about their shops losing money on their "diagnostic fees" due to parts places offering free scans... so someone took action.
T4R_Finally
New member
Your downstream o2 sensor is not going to make your rig run better. If its bad, it can stop you from getting catalytic deficiency codes.
Diagnosis
Thanks Mike I'd appreciate it. I don't want to throw parts at it either but I got a good deal on a couple of coils and NGK wires so I ordered them. I can always return the coils. I also ordered a bluetooth OBDII device and the Torque app for my phone to help diagnose. I plan on pulling the wires, coils and plugs and looking the whole thing over while it's torn apart so any help with diagnosis would be great. I'll post my findings and any codes this weekend, hopefully with a solution. Thanks to everyone who posted so far.
Thanks Mike I'd appreciate it. I don't want to throw parts at it either but I got a good deal on a couple of coils and NGK wires so I ordered them. I can always return the coils. I also ordered a bluetooth OBDII device and the Torque app for my phone to help diagnose. I plan on pulling the wires, coils and plugs and looking the whole thing over while it's torn apart so any help with diagnosis would be great. I'll post my findings and any codes this weekend, hopefully with a solution. Thanks to everyone who posted so far.
Toronto_T4R
New member
Thanks for the tip, and turns out you're absolutely right. Truck back to running like crap today. Ran great, felt good but when I turned it off to run into a store for a minute and fired her back up, the chugging and the CEL came back. Arg!
T4R_Finally
New member
You got a cel after changing the downstream sensor? What brand did you install? Do you have the code from the cel?
Toronto_T4R
New member
Sorry, that was misleading.
I had also been getting random cylinder misfire reads. Now my CEL is throwing misfire Cyl #5. It comes on and disappears. As you can guess, I'm new at the DIY game.
I've already changed out the plugs and wires (NGK), MAF sensor, air filter and more.
I had also been getting random cylinder misfire reads. Now my CEL is throwing misfire Cyl #5. It comes on and disappears. As you can guess, I'm new at the DIY game.
I've already changed out the plugs and wires (NGK), MAF sensor, air filter and more.
Update...
Ok got my 3 coil packs, NGK wires and bluetooth OBD2 scanner w/ Torque app. Gonna start pulling coils, plugs, and wires and checking all my vacuum lines. I'll update later.
Also pulled the codes. Old codes before startup were P0301, P0300 and P0171. New code upon startup was P0302.
Ok got my 3 coil packs, NGK wires and bluetooth OBD2 scanner w/ Torque app. Gonna start pulling coils, plugs, and wires and checking all my vacuum lines. I'll update later.
Also pulled the codes. Old codes before startup were P0301, P0300 and P0171. New code upon startup was P0302.
Ok this really sucks. Problem still there. Here's what I did today:
Pulled coils and replaced all three. Pulled wires (from 1999) and replaced with recommended NGK's. Pulled plugs and checked them, they looked fine no issues. Cleaned MAF and throttle body (again). Checked all the hoses I can see, no issues. Pulled the negative battery cable and EFI fuse to clear codes and restarted. Started right up with no idle issues. Drove around with bluetooth OBDII scanner plugged in and Torque app running. No issues, no codes.
Then I parked it and left it sit for about an hour and a half. Returned to the car and started up and immediately had a rough idle and felt like it was missing at low idle. Drove it with Torque app running and the CEL came on and stayed on. Got on the freeway and it started blinking at around 70 mph. Took it straight home and pulled the codes. It showed P0302 (Cylinder 2 misfire) and P0171 (System too lean Bank 1) again.
Any suggestions? Does seem to have narrowed it down to Cylinder 2 but what do I check/do next?
Pulled coils and replaced all three. Pulled wires (from 1999) and replaced with recommended NGK's. Pulled plugs and checked them, they looked fine no issues. Cleaned MAF and throttle body (again). Checked all the hoses I can see, no issues. Pulled the negative battery cable and EFI fuse to clear codes and restarted. Started right up with no idle issues. Drove around with bluetooth OBDII scanner plugged in and Torque app running. No issues, no codes.
Then I parked it and left it sit for about an hour and a half. Returned to the car and started up and immediately had a rough idle and felt like it was missing at low idle. Drove it with Torque app running and the CEL came on and stayed on. Got on the freeway and it started blinking at around 70 mph. Took it straight home and pulled the codes. It showed P0302 (Cylinder 2 misfire) and P0171 (System too lean Bank 1) again.
Any suggestions? Does seem to have narrowed it down to Cylinder 2 but what do I check/do next?
Ok. I'm going to pull all of the injectors today and check them with a meter. I'll replace any that don't check good and the rest I'm sending to Witchhunter Performance. For $22 an injector, they clean, test and replace any parts that can be replaced. Hoping this will end this saga...
Update...Help!!!
Ok I give. I just re-installed the fuel injectors after getting them back from Witchhunter. All of the injectors tested good but the cleaning definitely helped as evidenced by the test results. I put it all back together and it fired up with no issues. Started better than before and ran better as well. Test drove it and let it sit for about an hour to try and duplicate the problem that occurred before (see original posts).
Started it after about an hour and it fired right up and idled fine. Started driving and I felt a little hesitation. I accelerated to clear it out and the CEL started flashing then went off. Still no idle issues though. Drove it a bit farther and the CEL came on solid and stayed on. Went home and pulled the codes and it showed P0302 Misfire Cylinder #2 and P0171 System too lean. It still has no idle issues and sounds/runs fine so I am at a loss. :redbrick:
To summarize I have done the following:
Replaced spark plug wires with NGK's
Three new coil packs
Checked spark plugs (New Densos) (no cracks, gap issues, fouling, water or oil)
Removed all six injectors and sent to Witchhunter (all 6 cleaned and passed)
Reinstalled injectors
Cleaned plenum, throttle body and MAF
Checked vacuum lines and replaced two cracked ones
Replaced fuel filter
Seafoam in gas tank and through plenum
Any suggestions or help is appreciated...
Ok I give. I just re-installed the fuel injectors after getting them back from Witchhunter. All of the injectors tested good but the cleaning definitely helped as evidenced by the test results. I put it all back together and it fired up with no issues. Started better than before and ran better as well. Test drove it and let it sit for about an hour to try and duplicate the problem that occurred before (see original posts).
Started it after about an hour and it fired right up and idled fine. Started driving and I felt a little hesitation. I accelerated to clear it out and the CEL started flashing then went off. Still no idle issues though. Drove it a bit farther and the CEL came on solid and stayed on. Went home and pulled the codes and it showed P0302 Misfire Cylinder #2 and P0171 System too lean. It still has no idle issues and sounds/runs fine so I am at a loss. :redbrick:
To summarize I have done the following:
Replaced spark plug wires with NGK's
Three new coil packs
Checked spark plugs (New Densos) (no cracks, gap issues, fouling, water or oil)
Removed all six injectors and sent to Witchhunter (all 6 cleaned and passed)
Reinstalled injectors
Cleaned plenum, throttle body and MAF
Checked vacuum lines and replaced two cracked ones
Replaced fuel filter
Seafoam in gas tank and through plenum
Any suggestions or help is appreciated...
