99 Camry v6, high HC at low rpm

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ThurzNite

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I've got a 1MZFE 5sp with 216k miles. Didn't pass the low RPM HC test. Here's the results. There's no check engine codes before or after testing.



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Since the last smog check, I've changed a leaky power brake booster, Timing belt, water pump, spark plugs, associated seals, valve cover seals. All those were done earlier this year.

I've been having random P0401 even before I did all those things. I changed out the VSV vacuum switching valve when I changed the timing belts, made no difference.

My plan is to change the PCV, I haven't done that since 2008. I'll also change the tubes associated with EGR system. I'll also do another oil change, even though I just did it 2 weeks ago. Air filter was also changed 2 weeks ago. And throw in a bottle of Techron fuel system cleaner.

Anything else I should do?
 
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Seafoam through the power brake booster ahead.

Before you bring it in rev it up in 2nd or 3rd gear during a long freeway drive.
 
I always use premium shell or 76. But if Chevron is better, I'll do that. Chevron makes my car feel weak.

Seafoam, forgot about that. Will do!
 
Spark plug wires? I would run a tank of midgrade fuel with a can of berryman b-12 with a little italian tunup(just not hard enough to blow it up at 216 k!). then with the tank low add a lot of isopropyl alcohol and go for testing.
 
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Originally Posted By: ThurzNite
I always use premium shell or 76. But if Chevron is better, I'll do that. Chevron makes my car feel weak.

Seafoam, forgot about that. Will do!


Chevron is at least as good a product as the 76 is, plus it has a reasonable dose of Techron cleaner in it.

I would still pour a container of Chevron Techron CONCENTRATE
into the tank and drive till just about empty, maybe do this twice. Make sure get the "concentrate" and just the lesser version.

Seafoam...forget it. If anything it will damage the hose. If you can get a bottle brush just use that to gently clear the hose. STAY AWAY FROM HARSH SOLVENTS IN RUBBER HOSES.
 
In general, high HC is misfires.
No need to change 2 week old oil!
I'd run a good in tank cleaner like Techron or gumout Regane, or Redline SI-1.
New plugs and maybe wires.
All vacuum lines, connections, intake, PCV sould be checked and fixed as necessary.
Then go back afterwards and retest.
 
I did the oil change anyways, cuz the oil change I used 2 weeks ago was old stuff I had laying around (from 2006), and I don't think it was 5w30. I put in 5w30 conventional, with new filter.

Changed PCV and grommet

Seafoamed through the brake booster.

Threw in a bottle of Techron.

Seriously thinking of giving this a try too: http://www.amazon.com/CRC-05063-Guaranteed-Emissions-Formula/dp/B000CIPUR8

CRC Guaranteed To Pass.

To-do list:
Check resistance on coil packs and spark wires. After that, burn through this tank of gas, refill with more Chevron Premium, and retest.
 
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Originally Posted By: ThurzNite

To-do list:
Check resistance on coil packs and spark wires. After that, burn through this tank of gas, refill with more Chevron Premium, and retest.


I would not use premium for the test, 87 will ignite easier, unless its spark knocking on 87.
 
One thing I forgot to mention, you should get on highway for 15-20 minutes drive before go to the test facility, and let car idle if you have to wait more than 10-15 minutes for your turn. The engine should be at operating temperature for the cat to perform at peak efficient.
 
Originally Posted By: spasm3
I would not use premium for the test, 87 will ignite easier, unless its spark knocking on 87.

Wait, so my HC is high because my timing is advanced? So running regular 87 will retard timing, which should help lower HC, right?

Originally Posted By: HTSS_TR
One thing I forgot to mention, you should get on highway for 15-20 minutes drive before go to the test facility, and let car idle if you have to wait more than 10-15 minutes for your turn. The engine should be at operating temperature for the cat to perform at peak efficient.


The test only station was 20 miles away, I took the freeway there, took 20min. Parked the car for less than 5min (no wait). Next time I'll take longer route over there and do a few 0-60 runs just before pulling into their driveway.
smile.gif
J/K

What gets me is, no CEL, car runs like a champ, I'm getting better MPG than I ever have. I just don't get it! Thanks all who've replied.

edit: Forgot to add that fuel filter was changed this year too.
 
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Originally Posted By: ThurzNite
I did the oil change anyways, cuz the oil change I used 2 weeks ago was old stuff I had laying around (from 2006), and I don't think it was 5w30. I put in 5w30 conventional, with new filter.

Changed PCV and grommet

Seafoamed through the brake booster.

Threw in a bottle of Techron.

Seriously thinking of giving this a try too: http://www.amazon.com/CRC-05063-Guaranteed-Emissions-Formula/dp/B000CIPUR8

CRC Guaranteed To Pass.

To-do list:
Check resistance on coil packs and spark wires. After that, burn through this tank of gas, refill with more Chevron Premium, and retest.


Ahhhh... good call on the oil change then.
smile.gif


Yes on the other items too.

Don't forget to give us the results of the next smog check!!
thumbsup2.gif
 
Originally Posted By: ThurzNite
Originally Posted By: spasm3
I would not use premium for the test, 87 will ignite easier, unless its spark knocking on 87.

Wait, so my HC is high because my timing is advanced? So running regular 87 will retard timing, which should help lower HC, right?



no its just that 87 is easier to ignite.
 
The one thing I recommended you did not do.
And that is the plugs. And plugs are high on the list for HC misfiring.
I hope no harm was done by the Seafoam ingestion.
 
The coils and wires are low on resistance, so they're still good.

310 miles so far, 1/4 tank gas left. Will fill up later today. Probably the worst MPG I've ever had, driving "aggressively".

Just picked up some spark plugs, will install when it stops raining on Wed.

I'm concerned about getting the car warmed up. It's 50 degrees out and raining. I drove 45 min local and 3miles freeway. AC is on, fan speed low, temp dial set to hottest. My meat thermometer in the dash vent says 115-120deg. I was warm in my car, but not "hot". I'm wondering if the cold weather is preventing the engine from getting adequately hot (yeah, I know heater is radiator water, but still). What other methods of getting the cat converter hot on cold days?

Here is my blackstone, @3803 miles back in May 2011


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After that analysis, I did a Auto-RX. Just using regular dino oil right now, but previous to ARX, I've always used Mobil1.
 
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Wires can test OK with an Ohm meter, but leak or be otherwise bad.
The Ohm meter test is only for a massive internal break, or old wires with carbon breakdown..
 
If you already do your best to warm up the car and still no good, try new plug even if the old one is not yet at the mileage limit. Sharp edges help ignition and new plugs (even copper) with sharp edges like the NGK V power is very helpful for HC and CO (misfire).

With copper plug (or regular steel / nickle technically speaking) you can gap them smaller than spec so it will be even less likely to misfire (although lower engine performance).
 
I just put in some new sparks. I noticed Cyl 5 spark plug had oil around the crush ring. This's so weird because I just changed the seals when I did the timing chain and valve covers early this year. All 5 other sparks were dry.

Re-tested the coils and wires, all were well within specs.

I pulled out the EGR and cleaned it out. I forgot to clean out the corresponding ports the EGR attaches to. I'll get back to that tomorrow, then test the EGR with vacuum pump.

Any thoughts on running a mixture of e85 with 87octane?
 
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