P1349 Keeps Coming Back

With that many miles - pinging on regular gas on heavy loads (hills, high speed, etc) with that the 1ZZFE high CR - can sometimes be fixed by going with a higher grade gas. As a motor ages - there will be deposits that form that may necessitate a higher octane.

P1349 is a misfire or ignition issue under most general OBD-II - but Toyota spec'd OBD-II has it as a VVT malfunction. Unfortunantly - hard to tell which it is. Since it happened when you switched gas and after a bad cat - might be the ignition timing set too advanced (VVT-i issue) or low fuel pressure (bad or clogged injector, bad or low flowing fuel pump/regulator). An emissions test will tell you which one it is - with taking anything off the car, or a scanner put on aquisition mode and recording several parameters to see what the deal is. Other things could cause these same problems - but given what people reported having problems on these forums and the pinging issue - I'd lean toward the injectors giving you problems.

Seafoam and other additives are very good solvents - but may not be strong enough to clean off these injectors. Injector cleaning services generally don't work that well - best way is to have these cleaned ultrasonically or replaced (very costly).

Some pinging is normal and unavoidable - but sustained heavy pinging at highway speeds will quickly ruin a motor.

Can you fix it yourself - depends on what tools you have available and how much experience you have under the hood. I'd say that 90% of the time - you should be able to DIY. As long as you have decent documentation and correct tools - this is completely doable.

Good Luck.

Hard to say - depends on the what is wrong. There was an issue for the oil control solenoid on the VVT system - but I'm unable to find a link for you. If you search the site - there was a poster, bwringer, that worked on the VVT system.

Most dealers will change around $80 for diagnostics and anywhere from $50-$85 per hour for labor. Could be an expensive proposition - I would exhaust other possibilities before I go down that road.

Good Luck.

ALLDATA is a good resource for DIY. A good deal if you don't have access to a Toyota service manual or can't find one - worth the money?? only if you use it. Not sure what the TSB will give you - since I haven't seen Toyota take any action on this problem (VVTL-i systime issue is a different story).

Buying premium gas to help with the pinging is much cheaper than buying additives that boost ratings. There are additives that supposed to add more detergency as well as boost the octane - but most are very similar to what is in gas already. Better to stick with "Top Tier" gas outlets - higher levels of additives than what the EPA demands. Also read over the gas quality post here on this forum - good info it that.

Definitely sounds like a VVTi malfunction. If you get a P1349 that comes back, even after it is reset the first time around - and you notice significant power loss. Sounds like the oil control valve is faulty or the actual VVTi actuating assembly is faulty. Really no easy way to look at it until you open the engine up. There is a TSB that (TSB EG009-03) addresses this issue on certain models of Corolla, Celica, MR2 and Echo models built before a certain production change. This will be covered in the manufacturer 5/60 powertrain warranty, if you outside of the warranty, the tab falls onto you.

This is not an inexpensive fix - though if you have a decent handle on a wrench and a good service manual infront of you - you could be able to fix this yourself. Think of a P1349 problem as an engine that is not able to advance engine timing as needed or one that has the inital engine timing set too far advanced or too far retarded - all will result in poor performance. Some cases, the problem will be very minor - you just get some light off idle pinging. Some cases, the problems are so severe - the engine cannot maintain idle or will only run at idle speeds.

You can try sending a used motor oil sample to a lab and see if the oil comes back OK. If there are signs of coolant in the oil, high concentrations of wear metals, or the oil has completely broken down - you may be better off looking at an engine swap or dumping the car all to together. Not a real common issue - one of those things that some have the unfortunant luck to have and is also one of those things that is an expensive fix.

Could try some synthetic motor oils changed at a relatively short change interval (3K-5K drain interval) - the higher solvency of the synthetic will slowly dissolve deposits that might have clogged the oil control valve and maybe be able to reverse the situation with the VVTi system. I'd hold engine flushes and the like for last - as these tend to have a terminal result in engines that have serious problems. Good Luck.

Did the dealership replace the oil control valve filter? Unless the engine was significantly sludged over or had known oil issues (infrequent oil changes or poor maintenance) - then there is a good chance an engine flush has loosened deposits and completely clogged up the VVT actuator and associated components. Best to do short interval oil changes with a motor oil with good solvency (stronger detergents and dispersants) characterists

There is a technical service bulletin or TSB on this issue - TSB EG009-03 - that describes a troubleshooting procedure. But I'm not sure if it applies to your market Corolla. The TSB came about in 2003 and addresses this error code in certain production number Corollas, Celicas, MR2s, and Echos.

The oil control valve and the VVT actuator is pretty expensive, I would definitely not replace those until all other options have been explored first - but there is a small oil filter screen that runs to the valve. If that filter is clogged - you could get the P1394 code.

Being a 2003 model and UK or European market? - that TSB probably can't really help you - as those were addressed for the newer generation.

Could be one of those sensor "glitches" that will eventually go away. If you really did a VVTi malfunction - the engine should "ping" badly under load, have trouble keeping an idle, and overall drive poorly. Fuel economy will also drop considerably. If none of those happens - you may have an electrical issue. Very likely that there are some faulty engine/chassis grounds or a damaged wiring to the ECM, causing it to believe a sensor/system is failing.

Do you know what the Catalytic code was? I'm assuming that it was P0420 - Catalyst System Efficiency Below Threshold. Given the amount of time between those occurances, I would chalk this up to the ECM getting confused/bad tank of gasoline. Only way to know for sure is to backprobe the O2 sensors (both the upstream (pre-cat) and downstream (post-cat) sensors) and verify their output traces on a meter, preferably an oscope. This assumes that the sensors are working correctly, as it is common at this age/mileage to have a sensor start to get "lazy" or not quite fail or slowly fail on you.

You are correct in that these OBD-II codes only indicate logic failure in the ECM - they do not specifically say what part is faulty. The ECM can only ascertain failure (either directly or indirectly) from other sensor inputs. The code just tells the mechanic where to start looking. There are cases where a certain code on a certain model year is indicative of a common failure. The mechanic still has to do some diagnostic work to confirm his suspicions before any part is replaced. Also possible that the two codes might be interlinked - a possible VVT issue caused the initial P0420 code to pop up. Won't know for certain, unless diagnostics are being done. Note that some mechanics charge between $85-$105 per hour for diagnostic work - for this issue, I would make sure the shop has access to TIS (Toyota Information System - usually web subscription based) and is very familiar with this family of engine. Otherwise, I'd take the car to a Toyota dealership.

The P1349 - VVT issue does affect a wide range of Toyotas - most of them result in electrical issues (bad battery, loose chassis grounds, faulty wiring, etc.). Most of that you can diagnose yourself with a mirror and a good multimeter. There should be quite a bit of information online, including some PDF documentation on how to diagnose the P1394 code. Most involve checking for signal and power to the OCV and ECM. There are a few cases that the VVT malfunction is attributed to excessive wear on a plate from a pin in the VVT actuator itself. This cannot be diagnosed without removing the valvecover and disassembling the valvetrain. But there are "tricks" to see if this is the case - but unfortunantely, none are 100% absolute.

The instructions in WikiAnswers is fine - basically you are backprobing the O2 sensors. With a voltmeter, can be tough to spot problems, as the voltage signal is sinusoidal, which may be hard to see with some voltmeters (refresh rate). But still doable.

As for the PDF - I just Googled P1349 and got several links to PDFs. This one is for a Toyota MR2, but the diagnostic procedure is identical (same basic engine)

http://dutch.northwestmr2.com/Toyota/mr2%2...0(bank%201).pdf

Starting issue is completely separate from the VVT system, unless there was damage to the valvetrain as a result of a catastrophic VVT malfunction. More likely, it is an electrical connection issue with the starter (starter contacts) or even battery issue. Possible that the starter itself has gone bad - won't know for sure until you pull the starter out and have it bench tested. Earlier in your post, you mentioned the specifics of your car. Pretty hard to believe that the car is still on the original battery from the manufacturer. The OEM battery (Delphi in my car) lasted almost exactly 60 months - then completely died.

As far as possible damage from a VVT malfunction and the urgency to repair it? Depends on what part is causing the VVT malfunction to begin with.

If it is an ECM issue - then it is more or less an inconvenience. If there is something wrong with the OCV or maybe the actuator itself, it might require a new OCV or new sprocket head from Toyota. Basically you will need to rebuild one of the camshafts or a failure will cause engine damage (pistons will make contact with valves). In that worse case - you will need an engine rebuild or swap in another engine. Given what these cars are worth and whatever else is wrong with the car, might be easier to cut your losses and buy another car. But all of this is just conjecture until the car is properly diagnosed. Best thing to do - if the car is not running quite right (loss of power, engine stalling, idle is not smooth, engine pinging at speed, unusual noises), then reduce or completely stop driving the car until you are able to diagnose the problem right away. If the car is still running OK - then you have some time to figure this out. But time will eventually run out on you - find out what is wrong with the car and then you can plan on how to address the problem.

The worse thing you can do, right now, is just throw parts at the car - like 80% of the mechanics out there. Most will pull the code and say you need to replace this $300 or $500 part. If that doesn't work - you need to change this $300 or $500 part. If that doesn't fix it - you need to change X part for $X cost. All you have done is replace parts blindly hoping that one of them was actually defective. Most cases, I've seen people put in $500 to $2000 into a repair for a $10 part. Some cases, the car really did need all those parts - if the owner new that - they probably would have traded in the car for something else.

Hello and Welcome to the forum.

Headgasket? Maybe you meant valve cover gasket? That is not too hard to replace - you do have to watch the torque on the bolts (there are built in stops, but can still be overtightened) and make sure you have the correct gasket (comes with o-rings). You also need to add a little dab of gasket maker or RTV right where the timing cover meets the cylinder head - or there is a good chance that the valve cover will leak.

P1349 has many possible culprits - you really need someone that has experience dealing with the VVTi system on this engine family. Most common issues are mechanical in nature, so you don't have to worry about playing around with wiring - but the hard part is finding out where to start.

With any trouble code - make sure you start with a clean slate. Write down the exact code, reset the ECM (reset through scanner or pulling the negative terminal off the battery). I would suggest either borrowing an OBD-II scanner or buying one outright. They are pretty inexpensive, considering that the usually diagnostic fee starts at $85 at a dealership - plus you can diagnose issues right on the spot instead of taking the car in to be scanned.

I'd check the simple stuff - since you already had the valve cover off - did you notice any heavy deposits, gum, varnish on the valvetrain? I'd try cleaning the VVTi oil control valve filter - it is right below the OCV, both are right below the valve cover, closest to the serpentine belt. 9/10 times - if this filter screen is clogged, you will get a P1349 code and the engine will sound "rough", lots of valvetrain chatter. After that - it involves more detailed, exhaustive diagnostic work - both mechanical and eventually electrical. Try and avoid swapping parts out to find out what part is "bad" - lots of mechanics like to do that because it saves them time, but also costs you more money to pay for their "guess". Might be time to find a more qualified mechanic or bite the bullet and take it to a dealership. Good Luck.

Correct, the valve cover is on top of the engine, underneath the plastic engine garnish.

It is quite unusual to get an oil leak from a blown headgasket, usually it involves coolant issues (water jacket is closest to the outside of the engine there, oil is usually pumped in from the bottom).

If it was the headgasket - you have to check both the cylinder head and block for warping - otherwise the problem will keep returning (spent all that money for nothing).

Most common brands that you are likely to run into are Actron and Innova. Both make decent scanners - many support multiple protocals (CAN, ISO, PWM, etc.) - which wasn't the case before. Pretty much any scanner you can find will work just fine.

Online vendors, autoparts stores and major retail outlets are good places to look. The basic scanners run around the $50-$60 price range (Actron PocketScan and Innova 3030), the more expensive models generally add additional features like I/M compliance testing and freeze frame/data logging capability. Those are not critical for everyone - but they are very helpful features that can help diagnose the issue at hand, if you can make use of them.

I picked up an Innova 3100 scanner some years ago - usually retails for $100-$130, I got it at Wal*Mart for about $65. Sears sometimes will put some decent sales on their test equipment too - just keep an eye out for them.