There is no doubt that ahadith have been fabricated in praise of Muawiyah. Some have even written books in his praise, such as Ibn Hajar, whose book is titled “Tat’hir al-Jinan wa al-Lisan”. Also, some who refused to write such books were scolded and accused of being associated with the Shia. The thing to keep in mind is that this matter of fabrication was overdone so much to the extent that it entailed the objection of everyone, even of those who weren’t against the whole idea, and resulted in a great number of the Sunnis rejecting the hadiths and saying that there is no authentic hadith regarding Muawiyah (this is while they themselves would speak good of Muawiyah and were on his side). Sarakhsi says about Muawiyah: “قد کان هو من کبار الصّحابة رضى اللَّه عنهم و کان کاتب الوحى و کان أمیر المؤمنین و قد أخبره رسول اللَّه صلّى اللَّه علیه و آله و سلّم بالملک بعده فقال له علیه السّلام یوما: إذا ملکت امر امتى فأحسن إلیهم. إلّا أنّ نوبته کانت بعد انتهاء نوبة على رضى اللَّه عنه و مضى مدّة الخلافة فکان مخطئا فی مزاحمة على رضى اللَّه عنه تارکا لما هو واجب علیه من الانقیاد له، لا یجوز أن یقال فیه أکثر من هذا”. Also, Ibn Teymiyyah says: “و معاویة لیس له بخصوصه فضیلة فى الصحیح لکن قد شهد مع رسول اللَّه صلّى اللَّه علیه و سلم حنینا و الطائف و غزوة تبوک و حج معه حجة الوداع و کان یکتب الوحى فهو ممن ائتمنه النبى صلّى اللَّه علیه و سلم على کتابة الوحى کما ائتمن غیره من الصحابة”.
We have dealt with the topic of the fabrication of hadiths by Muawiyah in a separate article; as for the point you had in your question: there is no doubt that there have been ahadith forged in praise of Muawiyah, and this matter was overdone to the extent that everyone, even those for it, objected. Because of this, these hadiths were rejected by many Sunnis.
In this article, we will first speak about the endeavors of some in the field of hadith fabrication and writing in praise of the virtues of Muawiyah and Yazid, then we will see if there are any authentic hadiths about Muawiyah at all or not.
First issue: Some of the followers of the Sunni school of thought have fabricated hadiths about the virtues of Muawiyah and Yazid; what follows is a brief report of this:
The devotion of some to Muawiyah caused some false merits and virtues to be attributed to this man. Muhammad ibn Abd al-Wahed Abu Umar has a book about the virtues of this person who is stained with various vices. In Lisan al-Mizan (1:374), under the name ‘Is’haq ibn Muhammad bin Susiyy’, Ibn Hajar says: “This man has brought up some ugly things about the virtues of Muawiyah that Ubaydullah Saqati has narrated (from him), while he or his instructor have fabricated it all.” Ibn Hajar Makki has written the book “Tat’hir al-Jinan wa al-Lisan” on the virtues and merits of Muawiyah. Hafed Abdul-Mughith the Hanbali has compiled a book from fabricated material about the virtues of Yazid and Muawiyah!! Abu Umar al-Zahed has written a book using fabricated hadiths about the virtues of Muawiyah ibn Abi Sufyan, and Bardani used to fabricate hadiths about his virtues.
Studying the book of al-Shariah li al-Ajori (vol. 5, the chapter on the virtues of Muawiyah ibn Abi Sufyan) can also be helpful and informative for the respected reader regarding these ahadith.
On the one hand, in response to Allamah Hilli, who refers to the hadith of Teyr, Ibn Teymiyyah says: “None of the scholars of hadith have narrated the hadith of Teyr and none of them has verified it. Of course, this is a hadith that some have narrated, the same way they have narrated hadiths in praise of other than Ali and even many in praise of Muawiyah and have written many books about; but hadith experts have neither verified the hadiths about Ali, nor the ones about Muawiyah.” On the other hand, he reprimands Hakem Neyshabouri for not answering the call of those who had asked him to narrate hadiths on the virtues of Muawiyah and associates him with the Shia; this is while as we mentioned, he himself said that hadith experts don’t verify the hadiths there are on the virtues of Muawiyah. How can this clear self-contradiction be justified?! Of course, such an encounter isn't peculiar only to Hakem Neyshabouri; Nisa’i, the compiler of Sunan Nisa’i, has also been accused of being Shia, as is pointed to in Wafayat al-A’yan; the reason being that he has written a book titled Khasa’es Amir al-Mu’minin, and has been quoted saying: “I don’t know of any virtues of his (Muawiyah), other than Allah (swt) never allowed his stomach to become full.”
Also, Allamah Sarakhsi, in the book of Mabsut, chapter of Ikrah, says: “و ذکر عن مسروق، رحمه اللَّه، قال: بعث معاویة رضى اللَّه عنه بتماثیل من صفر تباع بأرض الهند فمرّ بها على مسروق، رحمه اللَّه، قال: و اللَّه لو أنّى أعلم أنّه یقتلنى لغرقتها و لکنّى أخاف أن یعذّبنى فیفتننى، و اللَّه لا أدرى أىّ الرّجلین معاویة: رجل قد زیّن له سوء عمله أو رجل قد یئس من الآخرة فهو یتمتّع فی الدّنیا؟!. و قیل هذه تماثیل کانت اصیبت فی الغنیمة فأمر معاویة رضى اللَّه عنه ببیعها بأرض الهند لیتّخذ بها الأسلحة و الکراع للغزاة ... و قد استعظم ذلک مسروق رحمه اللَّه ...، و مسروق من علماء التّابعین و کان یزاحم الصّحابة رضى اللَّه عنهم فی الفتوى ...، و لکن مع هذا قول معاویة رضى اللَّه عنه مقدّم على قوله، ... و إنّما قلنا هذا لأنّه لا یظنّ بمسروق رحمه اللَّه أنّه قال فی معاویة رضى اللَّه عنه ما قال عن اعتقاد و قد کان هو من کبار الصّحابة رضى اللَّه عنهم و کان کاتب الوحى و کان أمیر المؤمنینو قد أخبره رسول اللَّه صلّى اللَّه علیه و آله و سلّم بالملک بعده فقال له علیه السّلام یوما: إذا ملکت امرا متى فأحسن إلیهم. إلّا أنّ نوبته کانت بعد انتهاء نوبة على رضى اللَّه عنه و مضى مدّة الخلافة فکان معاویة مخطئا فی مزاحمة على رضى اللَّه عنه تارکا لما هو واجب علیه من الانقیاد له، لا یجوز أن یقال فیه أکثر من هذا.”
Allamah Amini, the author of Al-Ghadir, in rejection of the fabricated false virtues of Muawiyah says: “In this work we paid no attention to what Ibn Kathir says, nor to the call that some of those in the past heard from the mount of Shām (Syria); a call that goes: “Whosoever holds a grudge against Muawiyah, the flare of the fire will pull him into the burning hell and swallow him in its furnace!”, nor to the illusion that Ibn Kathir depends on in his argument that goes: “Someone has said: “I saw the prophet [in my dreams] while Abu Bakr, Umar, Uthman, Ali and Muawiyah were with him. All of a sudden a man came. Umar said: “O’ Rasulullah! This man belittles us. It seemed as if the prophet scolded the man for such, and the man replied: “I don’t look at them in a belittling way, but I look at him [Muawiyah]. The prophet said: “Woe to you! Isn't he one of my Sahabah?!”, repeating this phrase three times. Then the prophet took a dagger and gave it to Muawiyah and ordered him to stab the man with it and he did. I jumped from my sleep and quickly went home and learned that the same man had been killed that night and he was Rashed al-Kandi).”, nor did we pay attention to what Sa’eed bin Musayyab says that whosoever dies while liking Abu Bakr, Umar, Uthman and Ali, and believes that the ten will go to heaven, and sends blessings on Muawiyah (ترحّم علی معاویة), it will be upon Allah to take care of his reckoning.”, nor to the dreams that Umar ibn Abdil-Aziz has been said to have seen in which Muawiyah has been heard to say: “By the lord of the Ka’bah, I was forgiven!”, nor to what Ahmad Hanbal says: “What is their problem with Muawiyah?! We ask Allah for health and well-being.”. Of course, for information on the hadiths that can be found in Sunni sources about the virtues of Muawiyah and the answers there are for them, studying Al-Ghadir fi al-Kitab wal-Sunnah wal-Adab, vol. 11, pg. 92 and on suffices. For example, one of the hadiths Firdows al-Akhbar has fabricated in praise of Muawiyah reads: “انا مدینة العلم و علی بابها و حلقتها معاویة”. Although Sakhawi and Ibn Hajar Makki have clearly invalidated and rejected this hadith, Manawi has turned the blind eye to all of this, and has brought it in Kanz al-Haqa’iq.
It is good to know that Allamah Amini (ra), in this same book of Al-Ghadir, under the title of “A Research on Hadith and Characteristics of Fabricated Hadiths”, has stood up against those who accuse the Shia of hadith fabrication in an interesting and thorough manner, and has listed seven hundred Sunni hadith narrators who were liars and hadith fabricators, 43 of which alone, have fabricated around half a million hadiths. On top of that, he narrates about a hundred fabricated hadiths from Sunni narrators in which not only are the virtues and caliphate of the first three khalifas emphasized, but Muawiyah, Yazid, Mansur Dawaneqi and other khalifas of the Umayyid and Abbasid dynasties have also been praised!!!
Second issue: Are there any authentic hadiths on the virtues of Muawiyah?
Abdullah ibn Ahmad ibn Hanbal has said: “I asked my father about Ali and Muawiyah. He said: “Know that Ali has many enemies, and no matter how much they tried to find any fault or flaws in him, they couldn’t. That is why they gathered around one who had battled against him and provoked him to deceive and plot against Ali.” Hakem says: “I heard Abu al-Abbas Muhammad bin Ya’qub bin Yusuf saying: “I heard my father saying: “I heard Is’haq bin Ibrahim Handhali saying: “There is no authentic hadith on the virtue of Muawiyah.” Seeing that there are no hadiths in praise of Muawiyah, Bukhari saw no other option other than to add a chapter where mentioning the virtues of the first khalifahs, with the title of “A Remembrance of Muawiyah”; in Fat’h al-Bari (7:83), Ibn Hajar Asqalani writes: “This itself shows that the disputed virtues narrated about Muawiyah aren't authentic and have no basis. Many hadiths have been narrated about the virtues of Muawiyah, none of which bear a decent and acceptable chain of narrators.” Is’haq ibn Rahwiyyah and Nisa’i and others share the same view. Muslim and Ibn Majah who also weren’t able to find an acceptable hadith about Muawiyah, have added a page to their books in praise of the Sahabah. As for Teyrmidi, he hasn’t narrated more than one hadith (O’ Allah, make him a guider and a guided one and in a way that others are guided by him) saying that the hadith is “hasan sahih” (authentic). This is while the hadith is narrated like this: “O’ Allah guide him”. Ibn Teymiyyah in his book of Minhaj (2:207) writes: “Some have attributed certain virtues to Muawiyah and have narrated hadiths from the prophet (pbuh) about him, which are all lies.” Firuz Abadi, in the end of his book of Safar al-Sa’adah, and Ajaluni in his book of Kashf al-Khafa’, pg. 420, in the chapters of Muawiyah’s virtues, say: There is no authentic hadith in this regard.” In Umdah al-Qari, Eyni writes: “If you say that there are many hadiths on the virtues of Muawiyah, I will say yes there are, but none of them have authentic chains of narrators and are unreliable. Shawkani writes in Fawa’id al-Majmu’ah: “Those preserving the ahadith all agree that there is no authentic hadith on the virtues of Muawiyah.”
The conclusion being that, in order to free Muawiyah and Yazid from vices and impurities, some engaged in the act of fabricating hadiths but failed, and although some reject these hadiths, they still speak good of Muawiyah and attribute qualities to him, as was seen in the words of Ibn Teymiyyah and Sarakhsi.
 There is a saying in Farsi that goes: آش آنقدر شور بود که خان هم فهمیدصدای آشپز هم در آمد (meaning that the soup was made so salty that even the head chef himself complained).
 False and fabricated hadiths.
 Abaqat al-Anwar fi Imamat al-A’immah al-At’har, vol. 13, second section, pg. 35 and vol. 13, first section, pg. 126. For the answer to and rejection of the hadiths Ibn Hajar has listed, see: Al-Ghadir fil-Kitab wal-Sunnah, vol. 10, pg. 514 and on; Farsi translation of Al-Ghadir fil-Kitab wal-Sunnah, vol. 20, pp. 267-268.
 Farsi translation of Al-Ghadir fil-Kitab wal-Sunnah, vol. 10, pg. 120.
 Ibid, vol. 5, pg. 449.
 “الجواب من وجوه احدها المطالبة بتصحیح النقل و قوله روى الجمهور کافة، کذب علیهم فان حدیث الطّیر لم یروه احد من اصحاب الصّحیح و لا صححه ائمة الحدیث و لکن هو ممّا رواه بعض الناس کما رووا امثاله فى فضل غیر على بل قد رووا فى فضائل معاویة احادیث کثیرة و صنّف فى ذلک مصنّفات و اهل العلم بالحدیث لا یصححون هذا و لا هذا”; Minhaj al-Sunnah, vol. 2, pg. 207. The answer to this claim has been given in Abaqat al-Anwar fi Imamat al-A’immah al-At’har, vol. 13, second section, pg. 33.
 “ ان حدیث الطیر من المکذوبات الموضوعات عند اهل المعرفة بحقائق النقل قال الحافظ ابو موسى المدینى قد جمع غیر واحد من الحفاظ طرق احادیث الطّیر للاعتبار و المعرفة کالحاکم النیسابوریّ و أبى نعیم و ابن مردویه و سئل الحاکم عن حدیث الطیر فقال: لا یصح. هذا مع انّ الحاکم منسوب الى التشیّع و قد طلب منه ان یروى حدیثا فى فضل معاویة فقال ما یجیء من قلبى ما یجیء من قلبى”.
 Abaqat al-Anwar fi Imamat al-A’immah al-At’har, vol. 13, second section, pg. 38.
 Of course in Minhaj, he has said: “و معاویة لیس له بخصوصه فضیلة فى الصحیح لکن قد شهد مع رسول اللَّه صلّى اللَّه علیه و سلم حنینا و الطائف و غزوة تبوک و حج معه حجة الوداع و کان یکتب الوحى فهو ممن ائتمنه النبى صلّى اللَّه علیه و سلم على کتابة الوحى کما ائتمن غیره من الصحابة”. See: Abaqat al-Anwar fi Imamat al-A’immah al-At’har, vol. 15, pg. 415.
 Al-Nisa’i: “أحمد بن علی بن شعیب، ابو عبد الرحمن الحافظ، أصله من نسا (بفتح النون) من قرى خراسان، و جال فی البلاد و استوطن مصر فحسده مشایخها، فخرج الى الرملة بفلسطین، فسئل عن فضائل معاویة فأمسک عنه فضربوه فى الجامع و أخرج علیلا، فمات و دفن ببیت المقدس،و قیل: خرج حاجا فمات بمکة سنة (303)” Wafayat al-A’yan, vol. 1, pg. 21; As Safadi in Wafi bil-Wafayat, and Yafe’i in Mir’at al-Jinan, and Sabki in Tabaqat Shafe’iyyah, and Ibn Hajar Asqalani in Tahzib al-Tahzib, and Abdul-Haqq in Asma’ al-Rijal and Abul-Hajjaj Yusuf ibn al-Zakiyy al-Maziyy in Tahzib al-Kamal fi Asma’ al-Rijal have said in their biographies of Nisa’i.
 See: Abaqat al-Anwar fi Imamat al-A’immah al-At’har, vol. 15, pp. 411 and 415; Translation of Dala’il al-Sidq, vol. 1, pg. 7.
 Several points emerge from this passage, namely: 1- Masruq has said about Muawiyah: “I don’t know whether he is a man whose evil deeds appear to him as decorous, or a man who has lost all hope in the hereafter thus taking pleasure in this world.” 2-Sarakhshi admits that Masruq (which is of the Tabe’in) counts Muawiyah’s sale of idols a great sin. 3- Although Sarakhshi looks at Masruq the Tabe’i highly, he gives precedence to Muawiyah’s viewpoint regarding the permissibility of the sale of idols over that of Masruq’s. 4- Sarakhshi has become so upset by what Masruq has said about Muawiyah that he pointlessly begins to praise Muawiyah with false qualities. 5- Sarakhshi maintains that it is permissible to practice taqiyyah (dissimulation) and that it becomes lawful for one to put aside some of what is obligatory on him. See: Abaqat al-Anwar fi Imamat al-A’immah al-At’har, vol. 22, pp. 718-722.
 Tarikh ibn Kathir, vol. 8, pp. 139 and 140.
 To learn about these hadiths being fabricated ones, see: Abaqat al-Anwar fi Imamat al-A’immah al-At’har, vol. 15, pg. 415; Nafahat al-Azhār fi Kholasat Abaqat al-Anwar, vol. 12, pp. 165-171
 Al-Ghadir fil-Kitab wal-Sunnah wal-Adab, vol. 5, pg. 301.
 Of course, this isn't unusual, because in the introduction of Fat’h al-Bari, pg. 4, Ibn Hajar says: “Aba Ali Ghasani quotes Bukhari saying: “I have selected this collection of hadiths from 600 hundred thousand hadiths”, while we know that not counting repetitions, Sahih Bukhari contains no more than 2761 hadiths.
 Ibid, vol. 10, pg. 8.
 Tarikh Khulafa’ Suyuti, pg. 133; Fat’h al-Bari, vol. 7, pg. 83; Al-Sawa’iq, pg. 76.
 Al-La’ali’ al-Masnu’ah, vol. 1, pg. 220 [1/424].
 Sahih Bukhari, vol. 3, pg. 1373, chapter 28.
 Fat’h al-Bari, vol. 7, pg. 83 [7/104]
 The 10th part of Al-Ghadir has proved the inauthenticity of this hadith.
 Translation of Al-Ghadir fil-Kitabi wal-Sunnah wal-Adab, vol. 21, pp. 126 and 127, using the Nur al-Wilayah and Al-Maktabah al-Shamilah softwares.