I replaced my MAF with a new one, now my SES light comes on, code 34

the idle problem I had, a rough/stalling idle problem and hesitating while accelerating, that is all fine now, car drives and idles great, have never had so much power

my old maf showed no SES light, but it ran like crap as i said

following the service manual it said to unplug MAF and start, well now with this new MAF unhooked the car will not start, it starts and dies, with old MAF disconnected it would start and run

the problem started one day driving, car died, no start, towed home, no spark, replaced ignition control module from spare and started, however ran bad. Replaced the IAC and TPS, set both as per instructions here, except when setting the IAC, with the IAC unplugged the car starts and dies TPS is set at .54

just today i finally replaced my MAF, old one had a hole in the bottom, you could see the internal electronics, thats another story, lol, however it never threw a SES light

looking for any and all help, thanks in advance

 

 

Thanks for the pics, I tried to do as it shows in the flow chart, but when i disconnect the new MAF the car no start

I do have a service manual printed and in PDF form for my car, just cant follow it, other ideas? Could it be a relay?

 

yes it very well could be the MAF power or burn off relay. since theres no way I know of to test them. try another set. it couldn't hurt

 

So my MAF power and MAF burnoff relay both have the same number 14089936, i swapped the 2 relays but car would not start once this was done, put them back to orignal and starts right up, no SES, push gas to increase idle to over 2000 and wham SES, code 34

If it is the MAF then why no code on old MAF? Just ran like poop, brand new, cheap MAF, from rock auto, and now a SES

Also when i unhook this new MAF the car no start

help please and thank you

 

Welcome to MAF electrical issues. Replacement of the relays when installing a new MAF used to be common practice.
Replace them and check the harness wires going to them.

 

You may have corrected the MAF issue itself and are now getting what I like to call a false MAF code. Especially if the car is running well. A common cause of a false MAF 34 code is leaking fuel injector nozzles. Do you have a fuel pressure gauge? If so screw it into the test port and watch the fuel pressure with it running. When you shut the car off the pressure on the gauge should drop slightly but still hold pressure for several hours. If you the gauge goes to zero or the pressure drops down very quickly after shutting the car off the injectors are leaking.

 

connections are good, noticed my fuel pump relay connector needs replacing though, will order along with new relays

i will do a leak down test on the injectors, i did replace them last year with some bosch 3, but they came from ebay and not southbay, damnit hope its not the injectors, i hate learning the hard way, may need to order a gasket set to

many thanks, will post back after i get this done, later today

so if the maf power and maf burnoff are same gm part number, as they are in my car, why no start when i swapped them? does this mean one of them no work?

would a bad maf burn off cause code 34?

cause when i swap the 2 relays as long as both work, the car should operate the same, right? mine no start when i do this

going to see if i can get that part local, just sooooooo much cheaper to order from US, but i dont wanna wait, wanna drive my car b4 summer is gone

 

the MAF relays as installed from GM ,do NOT have the same part #.this may be part of your problem

 

There is more than just injs that can cause PSI drop, bad in-pump check valve, bad fuel psi regulator, leak in a line and of course, injs.

Fuel psi doesn't have to hold when you shut car off. As long as PSI comes up when you hit the key and while its cranking, your fine.

Never heard of leaking injs causing a maf code, how does that work? I could see a rich code thru the 02..

 

So i got a generic Relay from Nappa, matched the part number, swapped it for burnoff, same prob, cleared codes and tried it for maf power, same prob

what are the correct relays? i will be returning this one as it didnt make a difference

the only other thing i have done is put the stock prom in an adapter as the cold start injector was removed and the air/smog pump stuff also gone, however the chip was done for cold start only as smog/air was taken off after, but i dont see that being a issue

 

so i disconnected maf and got car to run with a lil extra on the gas, code 33
clear code
start car and check for 12V on red wire to MAF, 12V is good to go

does that mean faulty MAF ?

if so i guess leason learned, stay away from the cheap japo crap

 

Try to buy a new Bosch meter, pricey but.... These are very failure prone even when the cars were new.

 

no, its the CHINESE junk you have to avoid at all costs. if you bought a re-man MAF . well ,theres your trouble right there .THERE IS NO WAY but to buy a new one

 

so the new japo MAF was shipped back yesterday, waiting for my credit then i will be ordering a re-man AC delco MAF, will update

thanks again for all the help

 

I hate to tell you this,,but im gonna. ALL re-man MAFs are junk,trash,crap.no bueno,my friend.spend your money on a NEW one, once and done. if you insist on a re-man MAF. you, in the end WILL spend more time and money,trying to get it to work properly

 

even a re-man Ac delco? where can i get a new AC delco? No one here in Ontario, has em, can get a new cardone for almost 300, but i can get the same in US for 170

i havent ordered the re-man one, waiting on my refund first

 

I bought my new MAF from oreilleys. it is made by a company named "rich-porter". and a word of advice,A-1 cardone does NOT sell NEW anything. avoid their products at all costs. they may SAY its new but after a lil research it is revealed they re- man ALL their products in ......CHINA!!!! probably using rice ***** and wasp nests. I bought 7 of their MAFs before I got wise. im trying to help you NOT waste money and time.

 

I have a Cardone distributor which was NEW (was available as reman also, but I bought the new one) and both rear iron calipers which was Cardone reman. They all work great so I don't think all their products are crap?

 

maybe.but I don't trust them at all. after going thru so much BS with their MAFs

 

thought i woiuld add an update, just got a Bosch MAF, re-man AC delco, installed and now car starts and dies

i know, i was told to not get ac delco, but to use up my credit from rock auto, i went with what i thought would be a good replacement, orig equipment, i guess i was wrong


if i take my original MAF, car starts, no SES codes just runs like a pig

is there any testing i should do with this MAF, or since the car starts and runs with old one, and as soon as u take it out and put in new re-man one, no start

car will start with the re-man MAF installe das long as it is un-plugged but get code 33

Any and all help is appreciated, car has been sitting for past month, would love to be able to drive it again

Oh and my service manual says no start cause, defective MAF

Lost all faith in Rock Auto parts, looking for some help

 

may I suggest something? you need to find the factory part #s for your MAF burn off and power relays. THEN you can cross the part #s. and be sure you have the right ones .in the right place. THEN buy a NEW MAF from "rich-porter" . this one thing will ensure that you have the right parts. you SHOULD have no more issues after that. HOWEVER if you do still have issues, then you can think about a bad ECM and/or a bad MEMCAL/chip. think of it this way,yeah youre going to have to spend a lot of money. but you will be rewarded with a very satisfying car to drive after youre done. don't give up .and next year you can be proud and happy. good luck.

 

update to my update

Lesson learned, dont let others work on your car

I beleive I may have found why the first MAF gave a code 34, the wiring to MAF sensor was stripped in spots and the inside exposed, touching one another.. end of last season the ac delete pulley, that was installed at shop, broke off, this caused the MAF to get the hole on the underside where the electronics are, doesnt affect air flow, the idiot at the shop didnt fix the wires

Could the exposed shorted wires be the cause of the original code 34?

 

sure could. AND that kind of thing can lead to a dead ECM too.

 

Very good example of how a simple inspection of all the components in the affected system can save a lot of $$$ and time. I am an auto technician, NOT a parts guy, other mechanics will know what I'm talking about. Some customers might not like that as it takes an extra hour or two, but at least when they have to order a 500 sensor its not going to come back 3 days later with the same code.

Here is my own personal code 34 experience, on my own Trans Am, quite recently.

Would throw code 34 while vehicle is driving. Basically, clear code and would not store code 34 while moving around the parking lot into shop etc. Look up procedure and find same relay bulletin, confirm numbers and perform step by step procedure diagnostic. Everything tests good but as time goes on code is now setting hard all the time. This all happened with in 2 days. About one week after buying the car.

Decide one day after work to put my big boy pants on and starting doing a complete wiring harness inspection after it threw a burn off failure code as well, its too bad I didn't do it earlier, but found the problem.

A simple part failure, a few wire loom retaining clips had failed on the cooling fan shroud and the wiring harness was being forced into the pulley system on the front of the engine. When I first bought the car I noticed the wiring was not in place, but assumed it was just forgotten. SO I put them back in the retainers and didn't check them again until later on. This problem eventually caused the wiring to be rubbed through, the power wire to the MAF eventually was severed. This would also explain the initial intermittent code 34 appearing. When the vehicle was at rest or very slow speeds with the fan off the wire loom would somewhat naturally return to its original position against the cooling fan shroud.

 

exactly! many of us who have been through the MAF hell. have found that the WIRING is as much at fault as the damn Chinese parts!

 

After several remanufactured MAF and Codes 34 and 36 from the beginning or after a couple miles, I am looking for a new GM/Bosch MAF. I've had a lot of problems with remanufactured MAF over the past years.

Are they available anywhere in the world by 2025? www.thirdgenranch.com had new ones a few years ago.

Broken from the beginning or after 200 miles (two BSE remanufactured 27854 from Rockauto; Code 34/36):