Maybe totally unrelated, but on way to the garage to get the new exhaust fitted the engine seemed to be running sweetly with no hint of what was to come later (flashing engine light).
As time was getting late + needing to return home(left garage at 9pm Sat night ...they did try their best to sort this, but time constraints meant unable to solve)
obd reader demo'd slight intermittent misfire
tried swapping out coil-packs.
Next efforts to be attempted(by me asap) :- all coil packs + plug swap
Is there anything else obvious?
Symptoms :- new twin exit Zero exhaust sounds like a 2nd WW piston engined fighter plane, very much feeling that car is running on 3 cylinders, albeit without any obvious hesitation, a slight reluctance to rev.
Thoughts and Suggestions?
I looked at this with horror
'' Besides the obvious sound, you can confirm a misfire if your vehicle has:
A Flashing Check Engine Light: A flashing engine light is much more serious than an illuminated Check Engine Light, and you shouldn't keep driving if you spot one. When a flashing or blinking engine light shows up on your dashboard, it's almost always related to engine misfires. If you ignore the Check Engine Light, it could damage the catalytic converter or, in the worse case, start a fire.
Black Smoke From Exhaust: When your engine misfires, you might notice a cloud of thick, black smoke from the exhaust. This is often a sign that your engine is not passing fuel and air correctly and could be misfiring. ''
Did they check all the earths? Dodgy earth, totally unrelated to the manifold exchange, just coincidental, could give similar symptoms especially if it's crank or cam position.
One of two things must have happened related to the manifold swap.
1. Either something was accidentally disconnected or damaged during the swap.
2. The AF ratio parameters might have been on the edge and the increase in flow of the new header has exposed its demand for more fuel.
If the battery was disconnected during the install its probably that. Check and tighten the connections.
Check the air filter to make sure it not restrictive. Check the fuel trims to see if its subtracting fuel.
Check the O2 sensors
After that it might be a fuel related problem. Check the fuel trims to see if it is adding fuel beyond its limit. Not all fuel constriction causes a fixed CEL.
I reckon they touched the O2 sensors who took it as an opportunity to die.
Wouldn't hurt to refresh them anyway.
Have you swapped the manifold or back box? You mention twin exit exhaust but no mention of manifold so im a little confused.
Quote from: Iain on March 20, 2023, 12:53Have you swapped the manifold or back box? You mention twin exit exhaust but no mention of manifold so im a little confused.
Complete exhaust , so manifold,sports cat + backbox
I'm with JVZ on this one. The O2 sensors have been disturbed and one of them might have taken a knock in the process.
Try disconnecting the MAF sensor see if any better.
The lads Yaris SR was missing farting struggling to rev random misfire code.
Pinched the one off my roadster (same part no) sweet as a nut after.
Just a thought.
Yep as above, gotta go with O2 sensors. Sensitive little chaps at the best of time and hate being messed with.
Coil pack, plug, injector (all new Denso) swapped out on #4 (the left hand cylinder), along with a new 'universal' Denso O2 sensor.
Result : yellow light go's off at medium-high revs (when on the road) and stays off, car initially was bogging down + still occasionally firing on 3 with the yellow light flashing. Once the flashing light went off the car was far smoother and clearly would rev readily without issue.....this all sounds good.....but slowing down to normal speeds ie 2-3k revs , the flashing yellow light returned with a perceptible bogging down sensation.
Guy who helped is a skilled amateur auto-electrician, he reckons maybe one of 4 things now
1) coil pack wiring back to ECU
2) Injector wiring back to ECU
3) ECU connectors
4) ECU itself
Is there anything else obvious? MAF sensor has been mentioned by
@mr2garageswindon (will rob from one of my others to see if this works)
Disconnect battery, change MAF have a cuppa.
Re connect battery go for a drive all sorted happy days.
When the MAF went on the lads car was fine one day then ran like crap next day, typically just after I bought it back from a customer after 11 years of abuse and no problems at all.
Now consistently running on all 4 cylinders, whatever the solution was? probably a combo of everything, certainly the questionable O2 sensor splicing in from the original set-up to extend the cable to make it compatible with the Zero exhaust manifold, seemed to give the most immediate effect.
Whatever.....happy days ;D
Quote from: Gibla on March 30, 2023, 15:31certainly the questionable O2 sensor splicing in from the original set-up to extend the cable to make it compatible with the Zero exhaust manifold,
Ahh no mention that the wiring was extended to fit the exhaust in 1st post...
I think that would have raised alarm bells from the start.
Happy days its working now go do some donuts in it..
Quote from: mr2garageswindon on March 30, 2023, 16:33Ahh no mention that the wiring was extended to fit the exhaust in 1st post...
I was unaware until the amateur auto-electrician pointed it out,2 sets of joints, loosely wrapped in insulation tape< the 'joints' fell apart when taking the whole lot off. I was going to take a picture of the sorry excuse for good workmanship but somehow relented.
Zero recommended getting an extended O2 sensor that was from the Celica .....I should have bought that immediately. But now after using a universal fit heat-shrunk fitment all seems well. The other abysmal cable now a distant memory
Doughnut time ;)
I had no problem when I extended the cables on mine.
Quote from: J88TEO on March 31, 2023, 00:35I had no problem when I extended the cables on mine.
Watched the guy who eventually did it properly, as per usual with anything like this ...it depends on having the correct tools + following the instructions carefully .....even he started off by ignoring the guidance sheet + tried to solder a connection.....nah, no cigar, his soldering attempts failed. Then he was successful with a heat gun in doing a heat-shrink connection.
I also made several extended O2 cables with no issue. The important thing is using the right oxygen free collapsing crimps. Soldering is a big no not only for sensors but for most automotive wiring except for circuit boards
Glad you got to the bottom of it
Now time to enjoy the car and possibly share a few pictures and video clip
The final word on this now :D
Thanks to Jorens
@Karthoum who swapped out the MAF for a new one, along with swapping fuel injectors from a known smooth-running car, the saga is now over.
Probably a combination of various bits n pieces contributed to the sorry saga
new plugs,coil packs,MAF + O2 sensor were already swapped out along with 1 brand new Denso injector (that was found to be clogged up with green slime + sand) also had a different hole pattern to the others < was this an expensive fake?
Anyways swapping the injectors from one car to another proved that they were the ultimate culprit . Happy Days now engine + exhaust running sweetly with no trace of misfires or EMU lights